I little bit worried about "ready chasis" speed when i was ordering it, i thought that it would be slower. My original plan was to buy an RC car and rip it, but those are quite expensive.
I have found that thrift stores tend to carry a ton of cheapo RC toy cars, trucks, and tanks in the kids toy section, generally missing their transmitter.
Hacking these into robot bases (provided the gears aren't stripped and all the wheels and motors are good) can be a cheap way to go. Just something to keep in mind for future projects!