When GitHub Copilot launched at $10 per month, every VP of Engineering thought they'd found their productivity silver bullet. "Just $10 per dev!" they said. "What could go wrong?"
Everything. Literally everything goes wrong.
I've watched five different companies roll out AI coding tools over the past two years. Not one stayed under budget. Not one finished deployment on schedule. And every single one had their CFO asking uncomfortable questions about why their "simple $10/month tool" was costing almost $80k in year one.
The Three Budget Killers Nobody Warns You About
Usage Overages Will Fuck Your Budget
GitHub Copilot Pro+ hits you with $0.04 per premium request beyond the monthly allowance. Sounds reasonable until your senior dev starts using it for a React migration and burns through the monthly quota in two weeks.
Here's what actually happened at my last company: budgeted $2,000/month for 50 developers on Copilot. First month bill was $4,847. Why? Because the usage tracking is garbage and nobody knew that generating tests for legacy code counts as "premium requests." The billing dashboard shows you overages after you've already burned through the cash.
The GitHub Community forums are full of teams getting burned by unexpected costs. Stack Overflow has dozens of threads where developers complain about billing transparency.
Half Your Team Will Ignore It (But You Pay Full Price)
Forget the consultant fantasy of "60-70% adoption rates." In reality, you'll get:
- 20% of devs who use it constantly (burning through quotas)
- 30% who try it for a week and go back to Stack Overflow
- 50% who actively disable it because "the suggestions are garbage for anything complex"
But you're paying for 100% of seats while getting productivity gains from maybe a quarter of your team.
Tool Chaos Means Budget Chaos
Developers don't ask permission before signing up for AI tools. They'll use GitHub Copilot for autocomplete, ChatGPT Plus for debugging, Cursor for pair programming, and some random new tool they found on Hacker News.
Finance discovers this when the Amex bill hits. One company I consulted for found they had 47 different AI tool subscriptions across their 80-person engineering team. Total monthly cost: $7,934. Planned budget: $2,400.
DX research shows this tool sprawl problem affects 80% of engineering teams using AI tools.
This tool sprawl is a common problem across the industry. Engineering teams love trying new AI tools without considering the cumulative cost.
The Real Costs Nobody Mentions in Sales Calls
Security Review Hell: 3-6 Months of Delays
Your security team will lose their minds when they hear "AI tool that sends our code to external servers." Plan for:
- Initial security audit: $15k-$25k (external consultants because your security team doesn't understand AI)
- Legal review: 2-3 months of contract negotiations
- Compliance documentation: Every SOX, HIPAA, or PCI requirement means more paperwork
- Network configuration: VPN endpoints, firewall rules, proxy configurations
One fintech startup I consulted for spent $32,400 on security reviews before they could enable Copilot for 40 developers. Took them 4 months because their CISO kept finding new reasons to delay - first it was "data retention policies," then "cross-border data transfer," then some bullshit about "AI model training on our proprietary algorithms."
GitHub's enterprise security docs outline these compliance requirements.
Enterprise security teams fucking hate AI tools. GitHub's own security documentation is a nightmare of compliance requirements and CISO panic attacks about code leakage.
Training That Actually Works: $100+ Per Developer
The "just install and go" promise is bullshit. Developers need training on:
- Which prompts actually work (most don't)
- How to spot when AI suggestions are dangerous
- Integration with your specific toolchain and coding standards
- When to ignore the AI (most of the time for complex tasks)
Budget $100-200 per developer for proper training, or watch 70% of your team disable it after two weeks. GitHub's own training materials show realistic adoption timelines of 3-6 months, confirmed by Oracle's analysis of enterprise adoption patterns.
Integration Nightmare: 40-80 Engineering Hours
Getting AI tools to play nice with your existing setup is a shitshow:
- IDE plugins break with updates (constantly) - I've seen "ECONNREFUSED 127.0.0.1:8080" errors for weeks after VS Code 1.93.1
- CI/CD pipelines choke on AI-generated code that looks fine locally but fails in Jenkins
- Code review processes require new guidelines because AI loves deprecated patterns
- Git hooks break when they encounter AI commit messages with weird Unicode
- ESLint configs explode with AI-generated code patterns that throw "Parsing error: Unexpected token '=>'" everywhere
At my current company, it took our platform team four days to properly integrate Copilot with our monorepo setup. Turns out there's a bug where .gitignore patterns break Copilot's context window when you're running Node 18.x with specific pnpm workspace configs, but GitHub's docs don't mention this anywhere. Had to find the fix on a random GitHub issue from 2024.
GitHub's issue tracker is full of integration problems - VS Code configurations randomly breaking, JetBrains setup failing silently, and enterprise IDE management that's a complete shitshow.
The Code Quality Tax: 20% More Review Time
AI generates code that works but often violates your team's standards:
- Inconsistent naming conventions
- Missing error handling
- Security vulnerabilities (SQL injection, XSS, hardcoded secrets)
- Performance anti-patterns
- Dependencies on deprecated libraries
Senior developers now spend 20% more time in code review catching AI-generated problems. That's $18k-$32k annually in senior dev time just babysitting AI code for a 20-person team. I timed it for three weeks straight - went from 45 minutes daily in code reviews to almost 90 minutes.
The code quality problems are well-documented - security vulnerabilities, technical debt accumulation, and increased review overhead are common complaints in the developer community.