My experience with cheap turbo trainers is that they’re horrible. Never had an issue with build quality, just really hated using them. Often the resistance doesn’t go high enough for them to be of much use for training.
However, if it’s mainly for warm-ups, then I’d think pretty much anything would be fine. As many people buy them and don’t use them, they pop up a lot 2nd hand very cheap (although postage can be hefty due to the weight) so worth a look on eBay or the classifieds.
I know you aren’t looking for an expensive one, but should some budget creep come into play (ie x10!) then I’m loving my Wahoo Kickr.
Cheers, Rich