You can definitely find an good one in the $50 range, or a decent one much cheaper. Look for one with external sensors, especially for humidity, external sensors make a big different. I have expensive General Tools brand ones for work that I probably spent $60 apiece on Amazon that are more precise and can be (somewhat) calibrated and a super cheap one for home by Zilla that works fine.
For the Zilla one, temperature seems to be reasonably accurate, if a few degrees on the coolside (a note for measuring your basking temps - mine were typically 1 to 3 degrees higher than what the thermometer sensor read), while humidity is less accurate but gets you within 10% RH. I consider the Zilla one a "qualitative" reading - let's me know I'm in the ballpark. I generally leave this one in place instead of taking spot readings. You'll have to play with ones in this price range to get a sense for accuracy and back check them occasionally to make sure the readings haven't slipped.
If you want more precision and want speed with spot readings, go with something like Extech or General Tools. I have a General Tools "pen style" hygrothermometer that I use for work that I like a great deal. It's not this exact model, but close: