100 is kinda cheap no? Im not sure as far as acoustis go but I would go look at your used guitar shop in town. I got a nice Yamaha Pcifica for 200 canadian (around 140 US) at my used guitar shop in town. I dunno man, maybe ebay? They usually have good deals. Good luck.
you're not gonna find much under 150 and you won't want it after a month of playing...
go to long & Mcquade (if they even have one in ottawa) if their prices are the same over all of their stores you'll be able to get a epiphone acoustic for 150.
-Mike
Dude I was fine before you tried to turn me into a cake - me after ralphing after being antiqued