TL;DR: An AI receptionist costs two things: usage (~$0.07–$0.20 per call minute across voice platform, LLM and telephony) and the build/service (from ~$1,000 one-time for a simple agent to $15k+ for multi-location systems; agencies typically charge $100–$500/month ongoing). For most service businesses that's a tenth of a human receptionist's cost — for 24/7 coverage.
I build these systems for a living — receptionists and appointment setters for clinics, garages, real-estate teams and agencies — so this is the cost breakdown I actually quote from, not a vendor's pricing page.
The two costs people conflate
Running cost (usage): what the system burns per minute of conversation. Build + service cost: what it takes to create, integrate and maintain it.
Vendors advertise the first and bury the second; agencies do the reverse. You need both numbers.
Running costs, per call minute
| Component | Typical range | Notes |
|---|---|---|
| Voice platform (Retell/Vapi/Bland) | $0.05–$0.10/min | Bundles STT + TTS + orchestration |
| LLM tokens | $0.01–$0.05/min | Depends on model; small models handle most receptionist work |
| Telephony (Twilio/LC Phone) | ~$0.01–$0.02/min + ~$1–2/mo per number | Plus one-time A2P registration fees for SMS |
| Total | ~$0.07–$0.20/min | Premium voices push the top end |
Worked example — a dental clinic getting 300 calls/month averaging 2.5 minutes: 750 minutes × ~$0.12 ≈ $90/month in usage. A solo tradesperson missing 10 calls a week runs far less; a multi-location chain runs proportionally more.
Build costs (the honest ranges)
| Scope | One-time | What you get |
|---|---|---|
| Single-purpose agent | $500–$2,000 | Answer, qualify, take message or book into one calendar |
| Standard receptionist | $2,000–$6,000 | Booking + CRM integration + SMS confirmations + human handoff + missed-call textback |
| Complex / multi-location | $6,000–$15,000+ | Multiple calendars/locations, custom knowledge bases, compliance (HIPAA-adjacent flows), analytics dashboards |
Ongoing service (monitoring, prompt tuning, transcript reviews, integration fixes) typically runs $100–$500/month — worth paying, because what breaks in production is rarely the AI and usually an integration.
DIY? If you're technical, platforms like Retell make a self-built agent very achievable — budget a weekend for a demo and a few weeks of evenings for production quality. The build cost doesn't disappear; you pay it in your own hours.
Versus a human receptionist
- Human, full-time, US: $2,500–$4,000+/month — one shift, five days.
- AI receptionist: usage + service, typically $150–$600/month all-in — every call, 24/7, including the 40% of calls to local businesses that happen outside business hours or get missed entirely.
The honest framing: AI doesn't replace the warmth of a great front-desk person. It replaces hold music, voicemail, and the missed call — which is where the revenue leaks.
Questions to ask any vendor (or builder)
- What's the all-in per-minute cost at my call volume?
- What happens when the caller asks for a human? (Demand a live-transfer demo.)
- Is SMS A2P-registered? (Unregistered = confirmations silently blocked in the US.)
- Who owns the phone number and the CRM data if we part ways? (You should.)
- What does the monthly fee actually include — transcript reviews? prompt updates? integration fixes?
Want one built properly? My studio Null Studio ships these end-to-end — voice agent, CRM, textback, the lot. Book a discovery call and I'll quote your exact use case against the ranges above.