So i'm considering a trainer. I'm looking for one compatible with my 700 CC road bike as well as my wife's 26 in bike. I've seen a trainer on Amazon for $50, i've seen expensive ones for $600. I'm not sure what the difference will be between those options. I don't even know what features I care about, I don't have a cycle computer on my current bike. The purpose of the trainer is for if I don't get out super early I can still get a ride in when I have all the kids with me at night. (also to encourage the wife to ride more.... that is really the motivator). I tend to lean more towards the $50 version but if there is a big quality difference and benefit I could talk myself into the $200 range.

Any suggestions or recommendations?