I use a Epson 1640SU Photo (which means it's got the Transparancy Adapator lid) which is a generation or 2 before the above mentioned 2450. It's a 1600dpi scanner. It does up to 4x5 film scans, and does a good enough job with 35mm for previewing and web use. This could be a $30 ebay candidate (remember to factor in shipping as they are relatively large). It also does good quality and quick flatbed scans.
Some examples :