The best AI agency stack under $300/month — and the client count where it breaks

How this was checked

This is a pricing analysis, not a product test. Every figure came from the vendor's public pricing page, read on 1 September 2026, with the source and date listed at the bottom of this page. No account was opened, nothing was purchased, and no workflow was run — so this guide carries a Price checked mark and deliberately does not carry Workflow tested.

The constraint was written down before any pricing was read: a hard ceiling of $300 a month, covering lead capture and client delivery, for an agency running client websites. Excluded from the model on purpose, and worth stating plainly:

• Your own labour
• Hosting you already pay for
• Free tiers you already use
• HighLevel's usage charges for SMS, phone, email and premium AI — these exist, and their per-unit rates are not published on the pricing page at all
• Kinsta's overage rates for visits, bandwidth and storage
• Additional seats on any plan

Every price here is a monthly-billing price. That sounds like a technicality. It is the single biggest reason cost comparisons of this kind are wrong.

The annual trap

Five of the six vendors show an annual price by default. Only HighLevel opens on the monthly rate. So anyone comparing screenshots taken the same afternoon is silently mixing two different billing bases — and the resulting total is meaningless.

Two of these are worth pulling out. ActiveCampaign has no monthly toggle — the choice isn't defaulted, it isn't offered. And HubSpot's struck-through $20 is not its monthly price; it's the list price. The real monthly rate is $10, and both $10 and $7 are promotional, which the page discloses in a banner well above the plan cards where a screenshot is unlikely to catch it.

You can check all of this yourself in about thirty seconds. Open any two of those pricing pages and look at which toggle is already selected.

Prices that don't exist without JavaScript

Worth knowing if you ever try to check prices at scale: Writesonic and ActiveCampaign render their entire pricing tables client-side. Fetch either page without executing JavaScript — which is what most automated tools, and some AI assistants, actually do — and you get plan names, feature lists, and no numbers whatsoever.

An earlier draft of this guide reported that those prices were unpublished. They are published. They were invisible to the method being used. We corrected it by opening the pages in a real browser, and we're leaving this paragraph in because the failure is instructive: “I couldn't find it” and “it isn't there” are different claims, and only one of them was ours to make.

What the stack actually costs

Two categories are non-negotiable for an agency running client websites: something that captures and follows up on leads, and somewhere for the sites to live. Everything else can wait for revenue that justifies it.

The two limits that break it

HighLevel Starter includes three sub-accounts. Contacts and users are unlimited; sub-accounts are not. Client four has nowhere to go, and the next tier up is Unlimited at $297 — a $200 jump that alone consumes 99% of a $300 ceiling. There is no intermediate plan.

Kinsta's entry plan hosts one WordPress install. That is a single client site. Two clients means WP 2 at $70; five means WP 5 at $115. Hosting is the limit you hit first, and it is the one most stack guides quote at the $35 entry price regardless of client count.

Both boundaries are plan limits rather than prices, which is why they are invisible in a comparison built from headline figures.

Two things that changed while we were checking

This guide's figures were first gathered on 31 August and re-verified on 1 September 2026. In that one day:

• Kinsta restructured its pricing page. The old /plans/ URL now redirects to /pricing/, the layout is rebuilt around three audiences, and the billing toggle now opens on annual rather than monthly. Individual plan prices did not change.
• Kinsta added an agency tier starting at $340/month ($284/month billed annually, $3,400/year), bundling hosting credits, an unbranded admin experience and account management. That sits above this guide's ceiling, but it is the tier a growing agency gets pointed at next.

Both are the reason this site puts a read-date on every price. A cost guide without one is a guess about the past.

What to buy, and in what order

Buy first: lead capture and follow-up. At one to three clients, the thing most likely to cap your growth isn't delivery capacity — it's that enquiries arrive and nothing systematic happens to them. Fix that before you buy anything else.

Start on the cheapest plan that fits your client count and upgrade when a limit actually stops you, not before. At three clients or fewer that is HighLevel Starter at $97/month. Their pricing page offers a 14-day trial on every plan, so you can find out whether the follow-up automation is worth $97 to you before you are billed anything.

Reverse this order if you are onboarding a client whose site you have to build and host first. Then hosting leads and the CRM waits a month.

Buy second: hosting — but only once there is a client site to put on it. Kinsta Single is $35 for one install. The month you sign client two you are on WP 2 at $70, and at five you are on WP 5 at $115. Buy the tier you need this month rather than the one you might need next year: moving up is immediate, and there is no refund for capacity you never used.

Deliberately skip for now: SEO tooling at $139.95/month, AI-search visibility tools, and a separate email platform. Each solves a real problem. None of them solves a problem you have at three clients, and buying any one of them is what turns a $212 stack into an over-budget one. The trigger to revisit is a client paying specifically for that service.

The exception is if you sell one of these as a service. An agency running SEO retainers is buying Semrush to deliver client work, not to improve its own stack — that cost sits against client revenue rather than against this ceiling, and it should be priced into the retainer.

One caveat on the cheapest-looking option. ActiveCampaign's Starter is $15/month at 1,000 contacts, which reads like an easy addition to any stack. It is annual-only, so that $15 is a $180 commitment made once, and the price scales with your contact count rather than staying flat.

What we still could not verify

Published in full, because a cost guide that hides its gaps is not a cost guide:

• Semrush seats included per plan. Never stated. The page says additional users start at $45/month without saying how many you begin with.
• HubSpot Starter's baseline contact count. Not on the pricing page.
• How long HubSpot's Starter promotion runs. The banner says “a limited time” and names no end date, so $10 and $7 may not be the prices you see.
• HighLevel's per-unit usage rates for SMS, phone, email and premium AI. The pricing page footnotes that these charges exist and gives no numbers. For a lead-follow-up tool this is the line item most likely to surprise you.
• What Kinsta's agency tier includes at $340. The page lists benefits without specifying installs, bandwidth or storage.
• Whether Kinsta's “$0 for the first month” offer applies to every plan. It appears on the entry tiers; we did not confirm the boundary.

Sources

Every figure on this page came from one of these, opened in a browser on 1 September 2026. Software pricing changes without notice — confirm on the vendor's own page before you buy, and tell us if you find one of ours out of date.