What kind of buggy is this??
 

Looking to buy my 8 year old son this buggy, but the owner doesnt know the make and I don't want to buy it without knowing for when I need replacement parts.

The problem you may have will be finding pieces that make up the chassis. Drivetrain parts are pretty common amongst all brands. For chassis parts just use eBay. If the chassis is in good shape and it’s cheap I say go for it.