For basic filter coffee you're better off just grabbing a decent pour-over setup or a simple drip machine rather than anything fancy. Most of the budget machines under £100 are pretty reliable these days since they're basically just heating water and letting gravity do the work. I'd lean toward something like a basic Melitta or Philips drip machine - they're boring but they actually last. Check the reviews on the specific model though because even within the same brand you get duds sometimes.
If you want to be slightly smarter about it, look for machines with a metal filter basket instead of plastic, and avoid anything with a glass carafe that's permanently attached since those are nightmare to replace when they crack. The thermostat controlled ones keep your coffee warmer longer without cooking it, which matters if you're not drinking it immediately. Spend maybe £40-60 on the machine itself and you've still got budget left if something goes wrong. Since you mentioned DIY repairs, honestly the most common failures are the heating element or the thermostat, both pretty doable to swap out if you're not afraid of opening it up and checking what you're dealing with. Just be skeptical of the reviews saying "lasts forever" - people write those right after buying something.
One thing I'd actually consider though: a Moka pot or Aeropress is like £15-30, no electronics to fail, makes genuinely good coffee, and you can repair them basically never because there's nothing to break. Might sound weird but after watching so many machines just stop working for dumb reasons, the mechanical approach actually wins on reliability. But if you specifically want that traditional drip coffee convenience then yeah, grab a mid-range Philips or similar and don't overthink it.