I looked at slide scanners a while back. I have about 1,500-2,000 slides, but have moved to digital. Consumer Reports has a report on photo scanners within the last few years that you might want to look at. As I wanted a scanner with a pretty good resolution (4000 dpi or better), Nikon seemed to have the best product which also had a slide feeder, so that you could load 50 slides to be scanned, rather than one (or sometimes 3) at a time with most scanners. However, the price was pretty high (you can find them on Amazon, as well as other sites). I found the business represented by site below, which would scan all of my slides for significantly less than what it would cost me buy a scanner with feeder. It would also avoid the time required for me to scan all of the pics. I have not tried them yet, hoping for some feedback from someone who has used them.

http://www.digmypics.com/