I built StackMatrix: an open index of what B2B integrations actually cost (with calculators)

rakeshrkrk56-sketch — Tue, 20 Oct 2026 06:14:30 +0000

Every B2B integration page says "connect in minutes". Almost none of them tell you the connection requires a plan tier that costs 4× your current one.

So I spent the last few weeks auditing the official pricing pages and developer docs of 20 popular B2B tools, and built StackMatrix — a free, open index of what integrations actually cost: https://stackcostmatrix.com

What each of the 55 pair pages includes

An interactive True Cost of Ownership calculator (team-size slider, required-tier toggle, "I already pay for both apps" incremental mode)
The hidden cost trap: the exact tier gate, API add-on, or webhook paywall behind the "free integration" claim
A spec matrix (native vs API-only, sync direction, webhooks at the required tier)
Native vs middleware (Zapier/Make) total cost, compared honestly

Deep dives

HubSpot ecosystem cost matrix: https://stackcostmatrix.com/hubspot-integrations-cost/
Salesforce ecosystem cost matrix: https://stackcostmatrix.com/salesforce-integrations-cost/
CRM integration pricing guide (native vs Zapier/Make across CRMs): https://stackcostmatrix.com/crm-integration-pricing-guide/

Calculators worth trying

HubSpot + Slack — the $20/seat trap hiding behind a "free" integration: https://stackcostmatrix.com/stack/hubspot-and-slack/
Salesforce + Stripe — including the $25/user API add-on nobody mentions: https://stackcostmatrix.com/stack/salesforce-and-stripe/
Pipedrive + Xero: https://stackcostmatrix.com/stack/pipedrive-and-xero/

Open by default

The dataset is public and source-linked (every figure traces to an official vendor pricing page or developer doc): https://github.com/rakeshrkrk56-sketch/stackmatrix

Feedback welcome — especially corrections. Every price is re-verified against live vendor docs, and mismatches get flagged, never silently rewritten.

I Checked 20 SaaS Pricing Pages to Find the Real Cost of B2B Integrations — Here's What Vendors Hide

rakeshrkrk56-sketch — Mon, 19 Oct 2026 19:18:39 +0000

I run a small open project that tracks what B2B software integrations actually cost — not the sticker price, but the true monthly cost once you factor in plan-tier gates, API add-ons, and middleware fees.

Three findings that surprised me

1. Salesforce charges $25/user/month EXTRA for API access on Professional ($100/user). A 40-person team pays $12,000/year just for the right to connect their tools. This is buried in Salesforce's developer docs and never mentioned on their integration pages. I documented the full trap here: https://stackcostmatrix.com/stack/salesforce-and-slack/

2. HubSpot's Starter plan is $20/seat — but Breeze AI in Slack, advanced workflow notifications, and record-creation shortcuts all require Professional or above. The "free" Slack integration quietly forces a tier jump. Full breakdown: https://stackcostmatrix.com/stack/hubspot-and-slack/

3. The native-vs-middleware math flips at team size. A $30/month Make.com subscription often beats a $20→$100/seat tier jump. Nobody shows this math — so I built calculators that do, with a full TCO engine (total stack cost, incremental integration cost, first-year total, and 3-year TCO): https://stackcostmatrix.com/crm-integration-pricing-guide/

The open index

I put all of it into a free, open index — 55 integration pairs, each with an interactive true-cost calculator (team-size slider, required-tier toggle, "I already pay for both apps" incremental mode), a hidden-cost trap breakdown, and the exact minimum plan tier that unlocks each connection.

Browse all 55: https://stackcostmatrix.com
HubSpot ecosystem cost matrix: https://stackcostmatrix.com/hubspot-integrations-cost/
Salesforce ecosystem cost matrix: https://stackcostmatrix.com/salesforce-integrations-cost/
The dataset is open source: https://github.com/rakeshrkrk56-sketch/stackmatrix

Methodology

Every price is re-verified against live vendor pricing pages and developer API docs (all 40 source URLs are linked and timestamped on the About page). If a vendor changes a tier, the mismatch gets flagged for review — never silently rewritten.

Curious — what's the worst hidden integration cost you've run into?

DEV Community: rakeshrkrk56-sketch