I dont think Garmin is that bad tbh, I have the Garmin I3 bought from ebay for 120 pounds brand new and it has never let me down. If you want a budget one then it doesnt get any cheaper than that, plus you'll get speed camera locations pre-loaded on the memory card too.
yes it doesnt detect new ones or mobile ones but do you really need one? camera locations file can be updated via a website btw.