I would recommend that you hit the bike commuter thread for ideas.

Depends on where you live and how you commute. I street park and ride older, lesser recognized bikes. Depending on where you live, if you work late, etc..There's nothing wrong with a vintage, lower-end bike as a start . I street park and don't want to think about losing anything of value when I ride home at night. For the right price, as a beater/experiment in commuting - a low end bike may be alright. If you like it, you can always upgrade & learn once you find out that you like it.

Check out the commuter forum if that's what you have in mind. Under $100, it may be a good experience for you. Good luck