I'd hurry up and buy this bike at $139:
Vintage Maruishi Mountace MT18 Mountain Bike
It's a vintage mtb and the seller clearly knows what he has. Since the last pic shows the frame geometry; 22 inch frame is large for a mountain bike.
Plus the bike has good quality slick tires with a reflective stripe (that's a plus for commuting) and a rack.
Get it, ride it. By the way, this is a cool vintage mountain bike; well worth owning.
Oh yeah, once you buy it, post some pics and we'll help you set it up for commuting. This is a pretty unusual vintage mtb and you can't really go wrong at that price.