I use a Umax Astra 3400 that probably costs about 
$50 nowadays.  The only problem with Umax is that 
they're tech support totally non-existant, and 
their scanners simply don't work at all on 
certain systems.  So, unless you're guaranteed a 
refund (and NOT a replacement) from the place of 
purchase, don't get one.

I would highly, highly recommend a HP ScanJet 
4470c if you can afford it.  About $175 at decent 
places.

The scan below was taken by my Umax.  Even with 
cheap scanners, you can get decent looking scans 
if you scan at a high dpi (like 600) and then 
shrink.