The Pay-Per-Usage AI Stack That Replaced My $1,100/Month Software

A member in AI Avengers asked me last week: how do you run this whole operation? You have 3,000 contacts, daily email campaigns, SMS follow-ups, voice AI demos, and calendar booking. What does all that cost you?

I told her: pay per usage. She thought I was joking.

I was not joking. The same stack that used to cost $1,100 per month on GoHighLevel now runs pay-per-usage. The difference is not capability - it is who owns the infrastructure. When I owned it, the price dropped by 97%.

Why Most Tech Stacks Cost Too Much

Platform businesses like GHL bundle everything together and charge you a premium for convenience. You pay for the CRM, the email, the SMS, the funnels, the calendar, and the reporting - even if you only need two of those things. The bundling is the business model.

When you unbundle - take each function and find the best individual tool for it - you pay only for what you use. And most of what you use has a generous free tier or usage-based pricing that starts near zero.

The Complete Stack Breakdown

Here is every tool I use, what it replaces, and what it costs per month:

CRM: Jarvis (built on DuckDB). Replaces: GHL CRM, Salesforce Essentials, HubSpot Starter. Cost: Free. What it does: stores all contacts, tracks pipeline stages, logs every campaign interaction. Runs locally on my machine. I query it with SQL and I own all the data.

Email: Resend. Replaces: GHL email, Mailchimp, ActiveCampaign. Cost: Free (up to 3,000 emails/day). What it does: delivers transactional and campaign emails via API. I write scripts in Node.js. No visual builder. Deliverability is excellent because I control the sending domain.

SMS: Twilio. Replaces: GHL SMS, Podium, SimpleTexting. Cost: $15/month (usage-based). What it does: sends and receives SMS messages programmatically. I pay per message at Twilio's rates, not GHL's markup. Same capability, 60-70% less cost.

Calendar: Cal.com. Replaces: GHL calendar, Calendly Pro, Acuity. Cost: Free. What it does: handles all booking, reminders, and rescheduling. Integrates with Google Calendar. The open-source version is free and covers everything I need.

Voice AI: Retell. Replaces: GHL Voice AI add-on, Bland AI, VAPI. Cost: Usage-based (approximately $0.05-0.15/minute). What it does: handles inbound calls, qualifies leads, books appointments. I pay only when calls happen - not a flat monthly fee.

Database: DuckDB. Replaces: GHL database, Airtable, Notion databases. Cost: Free. What it does: runs fast analytical queries on all business data. Stores contacts, campaign logs, reply tracking, pipeline data. Sits locally on my machine.

AI Agent: Claude Code. Replaces: GHL workflow automations, Zapier, Make.com. Cost: $15/month. What it does: writes and runs code, manages campaigns, scans for replies, classifies leads, drafts responses. This is the brain of the whole stack.

Total Monthly Cost: Pay per usage (~$25-40 typical)

Twilio SMS: pay per message (~$15 typical). Claude Code: pay per token (~$10-15 typical). Mailgun: pay per email (free tier covers most). DuckDB CRM: $0. Total: pay per usage versus the $1,100/month flat fee I was paying GHL.

Annual savings: $12,840. That money now funds product development, team operations, and marketing. It is not savings in the abstract. It is capital I redirected into the business.

Who This Stack is Right For

This stack is right for you if you are running one business (not managing client sub-accounts), you are comfortable in a terminal or willing to learn, and you want to own your data and your infrastructure.

This stack is not right for you if you need a visual dashboard for non-technical team members, you are white-labelling software for 20+ clients, or you need enterprise support with SLAs. In those cases, pay for GHL or a similar platform. The bundled convenience is genuinely worth it.

How to Start

Start with email. Set up Resend, connect your domain, write one campaign script. That single step replaces the most expensive function in your current stack and costs you nothing. Once that runs cleanly for a week, add SMS via Twilio. Build piece by piece rather than trying to swap everything at once.

The full sovereign stack setup is documented inside AI Avengers Lab. If you want to build this with a community that has already done it: aiavengers.team/lab. Join AI Avengers Lab at $89/month — aiavengers.team/lab.