electric scooter drives & wheels for robot ?

Has anyone ever used the electric scooter drives & wheels for
robotics ? I saw one in the mall today for about $100 and it seemed
like a bargain given that you get 2 wheels + drive unit. The front
and rear wheels were different sizes, though. It was a "Razor"
brand. The rear wheel seemed perfect for what I want - just the
right size and "tackiness" - with built-in mounting points for a
sprocket or pulley!

So now I am on the (internet) hunt for replacement parts to see if
they are within my budget.

Anyone know how noisey the motors are ?

All comments are welcome!
JCD