I would say for what you are looking for you should be able to find for between $19.99-$29.99 per month which is a pretty realistic price for that much transfer. I just looking around here and maybe even posting an request in the "Hosting Requests" forum them do a little seach on the few hosts you narrow your choice down to and see if there is any feedback available about them.. and they are right stay away from anyone that offers the word "unlimited" when talking about diskspace or bandwidth.. good luck,,
HostRocket.com, they are a great company, I have been with them for a while and have no complaints at all. The best part about them is, their plans are very well priced, and offer a great deal of bandwidth. I think I pay $13.95 every 3 months, for 20GB bandwidth. Good stuff.