I tried the Protech 330T when they were on sale for $60 each in my Race GT8 and they did just as well as my RadioPost ($120each).
It is best to find a servo to fit your needs and budget.
But also try to stay up to date on the new technology and advances. I only say this because the last thing you want to do is spend your hard earned cash on outdated equipment. Example: most are running lipo Rx batteries for the benefits (lighter, more power and run time) is the price difference worth using a ni-cd or ni-mh battery pack? You don't have to buy the latest and greatest or new for that matter.
I buy and sell used gear all the time.