The real cost of per-seat alerting at 25 engineers

The invoice a CTO at a mid-sized Polish fintech showed me in March looked like this:

PagerDuty Inc.
Plan: Professional
Seats: 18
Per-seat (monthly): $21.00
Monthly total: $378.00
Quarterly: $1,134.00

12-month total: $4,536.00

My first reaction was the standard one: "you have 18 seats?" Second question: "how many people actually answer PagerDuty calls?" Answer: "four currently on rotation."

The rest of this post is about how the gap between those two numbers — four on-call engineers versus eighteen seats — builds a bill teams don't realize they're paying.

The 25-engineer math

Let's do it concretely. A 25-engineer SaaS team, mostly backend with some SRE. Half are on-call rotations, the other half occasionally get paged for code-they-own.

PagerDuty Professional is $21/user/month. The standard pitch is "you only pay for people on-call." That's true on the marketing page; it's misleading in practice. To page a developer when their service errors, that developer needs a PagerDuty seat. So in practice the seat count is your "people who might get paged" count, not your "people on rotation" count.

For our team: 16 seats × $21 = $336/month. Real cost.

Add Business plan if you want custom roles, deeper analytics, or advanced incident workflows: $41/user/month → $656/month. With Digital Operations Plus (the AI noise reduction tier) you're at $61/user/month → $976/month.

WardenPoint Pro is $29/month flat for the whole team. At any team size. Same channels (Slack, Teams, Telegram, voice, SMS, email, WhatsApp, Viber), same on-call schedules, same escalation chains, same custom roles.

So at 25 engineers, the per-tier math is:

Plan tier	PagerDuty	WardenPoint	Savings/yr
Professional	$336/mo	$29/mo	$3,684
Business	$656/mo	$29/mo	$7,524
Digital Ops Plus	$976/mo	$29/mo	$11,364

Annual savings range from ~$3.7K to ~$11.3K depending on which PagerDuty tier you'd otherwise need.

The «we already pay for it» trap

The cost argument hits an emotional wall: "We already pay for PagerDuty. The decision is sunk." This is the classic sunk-cost trap; the question isn't "what have we already spent" but "what will we keep spending."

If your contract renews monthly, the migration cost is the only sunk cost. We've seen most migrations finish in 2 person-weeks of work. At engineering salaries that's roughly $5-8K of labor. Pay back in 8–18 months on Professional, 4–9 months on Business, 3–5 months on Digital Ops Plus.

If you're locked into an annual contract, mirror until renewal and switch at the boundary. Cost of mirroring: zero, both tools allow multiple webhook destinations on the same source.

Three team sizes

Team size	Cost on PD Pro (annual)	Cost on WP Pro (annual)	Savings
10 engineers (~8 paged)	$2,016	$348	$1,668
25 engineers (~16 paged)	$4,032	$348	$3,684
60 engineers (~40 paged)	$10,080	$348	$9,732

The bigger the team, the wider the gap.

What you give up

This isn't pretending WardenPoint is feature-equivalent. Honest gaps vs PagerDuty Professional:

• No native postmortem authoring tool — we write postmortems in markdown anywhere and link them; PagerDuty has a built-in editor with stakeholder review
• No PagerDuty Marketplace — if your workflow depends on Atlassian Cloud add-ons (Halp, Statuspage, Compass), they have no first-party WardenPoint equivalent (webhooks bridge them, but lossy)
• Less polished integration directory — PagerDuty has more pre-built connectors; we have the popular ones (Grafana, Prometheus, Sentry, Datadog) covered

If those gaps are core, the cost calculus is different. If they're not, the flat fee is hard to argue with.

The deal at the edge

If you're under 5 engineers, PagerDuty Free is $0 and the cost question is moot. The flat-fee argument starts mattering somewhere around 8 engineers, gets compelling at 15, and becomes "why are we still paying that" by 30.