I am a BIG fan of Janome machines. I have a few that I used as teaching machines, as well as a Janome serger. All of my Janome machines have been used and abused, dropped, fallen off a moving truck, everything you can possibly think of and they just keep on ticking! If you're looking for under $100, I would probably go for the Janome 11558. Keep in mind that if you buy a machine from a local dealer, they usually throw in a free "get to know your machine" class. The machine will cost more, but it might be worth it if you've never sewn before.
http://www.overstock.com/Crafts-Sew...wing-Machine-Refurbished/3644244/product.html
http://www.overstock.com/Crafts-Sew...wing-Machine-Refurbished/3644244/product.html