Fisher Xcal Value
 

Hi Everyone,
I’d like to get my 12 year old son a mountain bike.
im wondering whether a Gary Fisher XCal in a Good Will would be a good first bike. Or even for myself.
If you could let me know what you think the value is and whether the number “17.5” in one of the pics refers to size, I’d appreciate it. Thanks!
see link here: https://www.shopgoodwill.com/Item/70046304

How tall is your son? 17.5 is usually a medium