Help me build a home server - eviltoast

Help me build a home server with a budget of €100/$109 (I live in Denmark)

I am thinking of buying it used how much ram who’d i need and what CPU

What I want to run on it

Nextcloud

RSS feed

transmission (if possible for the budget)

Maybe a few other small services

Photoprism (if possible for the budget)

Is this realistic for my budget?

Edit: Thanks alot for your really helpful comments