Tool · Price comparison
Confused by different pricing models? Put every AI support quote on one basis.
Vendors price AI support three different ways — per message, per session, and per resolution — which makes quotes almost impossible to compare. Enter any one rate and this converter translates it into the other two, then shows the effective cost per resolved issue: the only number that maps to business value.
How the converter calculates
The formula: divide the cost of a session by the resolution rate.
Two inputs do all the work. μ (mu) is the average number of AI replies in one conversation. ρ (rho) is the share of conversations the AI actually resolves, from 0 to 1. Every quote is first turned into a cost per session, then divided back out:
- 1 · Normalise to one session
Cost per session = per-message rate × μ, or the per-session rate as quoted, or per-resolution rate × ρ.
- 2 · Per message
Per-message cost = cost per session ÷ μ.
- 3 · Per resolution
Per-resolution cost = cost per session ÷ ρ.
- 4 · Effective cost per resolved issue
Effective cost per resolved issue = cost per session ÷ ρ. Unresolved sessions still cost money on per-message and per-session meters; dividing by ρ spreads that cost over the issues that actually got fixed.
Worked example. A $0.15 per-message quote with μ = 4 and ρ = 0.70 costs $0.15 × 4 = $0.60 per session, so the effective cost per resolved issue is $0.60 ÷ 0.70 = $0.86. A $0.99 per-resolution quote at the same μ and ρ stays $0.99 per resolved issue, because unresolved sessions are not billed. The cheaper-looking unit is not always the cheaper bill.
Want the real number for your operation?
Book a working session — we will price your actual volumes and intent mix, and show you the effective cost per resolved issue.
The three meters
Why the same AI can look 5× cheaper or dearer.
Per message
Billed on every AI reply. Looks cheap per unit, but multiplies by how many replies a conversation takes.
Per session / conversation
Billed once per conversation, regardless of how many replies. The unit most vendors quote.
Per resolution
Billed only when the issue is resolved. The unit that maps to business value — but definitions of “resolved” vary.
For the full methodology, worked examples, and how Aissist’s $0.20–$0.60-per-resolution model compares, see the cost benchmark of AI service.
Vendors on one basis
Fin, Zendesk, Decagon, Sierra and Gorgias, by the meter they actually bill.
Each cell is taken from the vendor's own page or marked Not published, with third-party procurement figures labelled “reported”. Effective cost uses the formula above at ρ = 0.70 and μ = 4, and leaves out seats and platform fees, which are listed in their own column. Rates as of 23 September 2026.
| Vendor | Billing meter | Rate | Bills unresolved conversations? | Fees on top | Effective cost per resolved issue | Source |
|---|---|---|---|---|---|---|
| Aissist.io | Per AI interaction, capped per resolution | $0.09 / interaction, capped at $0.60 / resolution (published) | No — escalations are free | None — no platform fee, no seats | $0.36 (4 × $0.09); never above $0.60 | aissist.io/pricing |
| Intercom Fin | Per outcome | $0.99 / outcome (published) | Partly — 24 h of customer silence bills as an “assumed resolution” | Seats $29–$139 / agent; 50-outcome minimum | $0.99 + seats | fin.ai/pricing |
| Zendesk AI Agents | Per verified automated resolution | Not published (buyers report $1.20–$1.50) | No — only LLM-verified resolutions bill, judged by Zendesk's model | Suite seats $55–$115 / agent | $1.20–$1.50 + seats (reported) | Zendesk help center |
| Decagon | Platform fee + per conversation | Not published (reported ~$0.99 / conversation) | Yes — the default plan bills every inbound conversation | ~$50K / yr platform fee (reported) | ~$1.41 ($0.99 ÷ 0.70) + platform (reported) | Vendr |
| Sierra | Outcome-based, custom contract | Not published (reported ~$1.50 / resolution) | Routing conversations bill per conversation; upsells and saves count as outcomes | ~$150K+ ACV; $50K–$200K setup (reported) | ~$1.50 + platform (reported) | Sierra on outcome pricing |
| Gorgias AI Agent | Per automated resolution | $0.90 (annual) / $1.00 (monthly) per resolution (published) | No — but each AI-resolved ticket also bills as a helpdesk ticket ($0.32–$0.40) | Helpdesk plan; $1.50 overage beyond bundle | $1.22–$1.40 (resolution + ticket fee) | Gorgias on AI Agent pricing |
All eighteen vendors, with fine print and provenance tags, are in the AI Agent Pricing Benchmark 2026.