Originally Posted by
Shadoninja
Ah I thought of another question! Should I care if my mtb has rear suspension? I have used bikes like that in the past and found them quite nice on the bumpy trails.
Full suspension is nice for bumpy trails. The problem is that it makes the bike more expensive and steals energy on smooth riding. And again, you want a quality full suspension bike not a WalMart special, so you're looking at $1000+ even on the used market.
I think your plan of commuting on a decent used 29er hardtail is an excellent idea. If you find you really get into mountain biking you'll probably want a better no what you buy. Make sure to figure that you'll likely want to spend ~$100 on any used bike for a tune-up and any potential replacement parts.
Not a 29er, but a decent example of what you can probably find:
https://boulder.craigslist.org/bik/4842797064.html
I'll post for others to offer comments.