Better alternative to HD 1501MG Metal Gear Servo for more torque?

This seems to be a great servo for my price range, but I'm new to this and wondering if there is a 'stronger' competitor.

Speed is fine, but hoping for a little better torque in the $20 or under price range.

I can give it more voltage (e.g. 7.5) if that helps. Can spend a bit more if that is necessary. Will get a lot of usage, as I have it connected to Dragon's eyelids for blinking.