You could possibly return the most recent purchase to CEX.
I don't know other brands, but in terms of a budget starter camera setup:
- Canon 350D, 400D, 450D, 500D - £ 30-£50.
If the camera doesn't come with a lens, you'll need one.
- Canon 18-55 "kit" lens, possibly one with image stabilisation, around £ 30 on ebay for one thats not sold as broken.
and maybe consider buying a longer lens as you're used to a x10 zoom on the compact.
- Canon 55-250 IS zoom lens or Sigma 70-300 APO - around £ 65 on ebay for a fully working one, possibly less
You'll need a memory card (Compact Flash or SD depending on the camera), possibly a spare battery and a padded camera bag. Stick it in auto to start with and experiment.
If you end up with a camera and need a memory card, I'll send one free. Others may be similarly generous with bits and bobs.
The potential quality you can achieve from an old DSLR and basic kit is actually very good, it requires some patience, some learning, and some experimenting, and above all a wish to learn.
You could start a '52' project. One photo on a given theme / topic per week. Submit photos for kind comment and critique. Week 1 of 2022 was "NEW", week 2 was "OLD", and week 3 was "RECEPTACLE" How you interpret the theme is up to you. There is nothing stopping you doing this with your current cameras either.