Several years ago my choices for cheap servos from reputable manufacturers were the Futaba S3305 MG and the JR Sport ST125mg (predecessor to the ST126). When I need more servos I will again buy the S3305 or the ST126mg.
I use them with Li-ion batteries regulated to 6 volts in 3D models powered by OS 1.60FX glow 2-stroke and 26cc to 36cc gas 2-stroke engines. My largest 3D planes have a 76-inch wing span and can do knife edge loops with one S3305 servo on rudder.
Don't need no stinkin' $100 servos or juice suckin' buzzing digital servos.