Definitely worth the penny to use a high quality servo. I toyed with the cheap 995's and cheap hobbycity's to try them out. I found them sloppy and even caused glitch problems with my radio. I gave them a shot before I went back to my trusty old Hitec 645.
Then I spent the money on some nice servos and wont look back.
A good $75 brand new servo is the
Futaba BLS452. These work great and are super strong!
I'm using a JR9100T in my 8-T and its amazing. I'm using a Futaba 9351 in my 8-B and its on the same page as the JR, amazing. Both of these are over $100 but are incredible and worth it.
Now you could find a Hitec 645, 5645, or 985 used for pretty cheap and those are great! great! servos as well.