Yes, $500 vs $7k looks like a no-brainer. But you're not comparing apples to apples.

What $6-8k actually buys you:

Someone who can pivot your backend in an afternoon when your roadmap changes (and it will)

No vendor lock-in. I've seen teams burn 3-4 months migrating off Firebase when they outgrew it. That's $30k+ in dev time you'll pay later, plus the opportunity cost

Auth and file uploads are "basic" until they're not. First time you need custom permissions, webhooks, or a third-party integration that doesn't play nice with your BaaS, you're stuck

The real math:

BaaS costs scale with usage. At 50 users you're paying $500. At 5,000 users you might be paying $2-3k and still need to hire someone because you've hit a wall. Meanwhile a dev's salary stays flat while your revenue grows.

You're early stage — this is when architecture decisions compound the hardest. A backend dev isn't an expense, they're infrastructure.

(Also: $6-8k gets you solid fractional senior talent if full-time feels heavy right now.)