I use a wide range of servos. if you dont need beastly servos then some of the cheaper chinese brands will work like Bluebird, Towerd pro mg996R (dont buy the mg995 though they suck), Stock Losi XXL servos are ok, and the EXI, servos are ok too. Most of those types of servos can mostly be bought from china for 7-20 each.
My favorite budget Servos though are sold buy a guy on Ebay named "CheapServoMan" He has some PPP brand 244oz/in .13 sec digital servos that are very smooth and quite and so far (about 6 months) havent had any failures yet. His servos prices tend to fluxuate between 22-45 bucks ea. IDK why his prices fluxate but they do. If you can pick these up for 22-30 bucks ea I think they are totally worth it. I dont think Id pay much more than 25 or 30 bucks ea for these though cuz for about 50-60 bucks you can get a savox with about the same stats.
If you really want a high quality high torque servo though you have to look towards companies like hitec, savox, futaba, and airtronics. those kind of servos in very high toques will run you probably somewhere between 80-100 bucks.