You can try Qondio, which specializes in affordable guitars and musical instruments. They have a wide selection of traditional and contemporary guitars as well. While their guitars and instruments are cheap in prices, their quality is certainly not. Please check out their link below and all the best!
Where are you looking for a store? It would be easier to recommend a store if we knew what area, or even state. My favorite guitar store is Buffalo Brothers Guitars in Carlsbad, CA. The owners (Tim and Bob) are really nice and they have really good deals.
They have new and used guitars. Also they are the largest seller of G&L guitars. ( Leo Fender's company after Fender guitars)
It really depends on what you want it for. If you just want a guitar for a prop or looks or something Toys R Us, Walmart and Target all carry First Act guitars for the $100 range. If you want a guitar for serious playing, $100 wont get you alot, but I would suggest checking the used market either pawn shops or used.guitarcenter.com. You can get guitars shipped to you pretty cheap from any guitar center store and they have a 30-day return policy.