Used Hitec servos in my 50cc models and continued to use it in my first small Viperjets, As many people around here were using the Graupner DES 707 BB MG I tried it in a Boomerang Sprint and I'm really very satisfied with the quality/reliabilty (a bit more then 100 flights, a friend of mine has over 300).
For my new 2.5 Viperjet I am using now the Graupner HBS 860 BB MG as I switched now to high voltage servos and this servo was used by some CARF guys.
My actual experience for now is that you don't have to spent over a hundred bucks for a servo. It must not be the cheapest (DES 707 is just around 30€) but there are a lot of excellent choices in the price range of 70- 80 $ that do the job. For all "normal " sportjets just get a branded standard size servo with metal gear and a torque from 180 to 220 oz-in .