$0. I run my own server and have solar.

100% free tier. I'm not in a tech industry atm. But when (not if) an idea reaches people and I'd need to up my game I'll start spending.

I don’t get the question

$0

0

Personally or professionally? Personally, under $100/mo. Professionally, usually over $500/mo and sometimes over $1000/mo. Thankfully, the company foots the bill.