"This motor is good for driving small, lightweight constructions at high speed. If you gear it up with a 24 tooth gear attached to the motor and driving an 8 tooth gear, this is an excellent thing to use with the pneumatic small pump, and if you switch the gears, they can drive a large pump with moderate effort.
In all, I would say that $7 is a good price, possibly a LITTLE too high with shipping/ handling added, but good enough for most people. Of course, you do need an $8 battery box (and six AA's) to use it... But oh well. It works!"