I'm a high schooler looking to build a few electric go-karts over the summer for me and my buddies. I'm mainly curious if anybody has any motor recommendations that are moderately priced. We are hoping to spend around $500 all in; including materials to build the frames. Are the $200 motor and controller kits on eBay worth it or should I be looking at motors in the 3 or 4 horsepower range? I'm mostly mechanically oriented and have little to no knowledge on motors; aside from basic technical jargon. Any and all input will be greatly appreciated!