Troy Built Models has 985MGs for $57. By far the cheapest that I've found. I'm using them in my 71 slick and 74 Edge. Do yourself a favor and just use 985s if you can afford them. Don't go cheap with the 5625s.

For these 30cc models, I've found you can go cheap on other parts like batteries, servo wires, motors, ECSs, props (APC),etc. But the one thing I've found where the higher price really is justified is a good servo. It makes ALL the difference. Kind of like the speakers on a stereo system. You can have a bunch of crap in terms of the amp, MP3 player, etc, but use good speakers because that is what you'll notice.

PS....you'll love the slick on 985s. A lot of guys also like the Savox TG and its Align Equivalent. I'm not talented enough of a 3D flier to notice the difference in speed and I think the 985s are already blazingly fast when you tap the sticks.