Nikon scanners may be old, but they work. A few years ago I bought a Nikon 4000 (I think that's the model) on Ebay and when I was done I sold it there at a profit. Try to get one with an auto feeder. Nikon's auto feeder jams a lot, but it's better than hand feeding.

Some observations: Kodachrome slides last very well for decades; other films not so much.
Lots of slides were not as sharp or well-exposed as I remembered.
Dust embeds itself in the emulsion and can't be blown off. My solution was a dust and scratch remover Photoshop plug-in from Polaroid.
Faded slides were often much improved by a Kodak plug-in called ROC. This may stand for Restoral of Color.

Good luck,
Jim

I spent a number of weeks scanning a few hundred old slides. It became obvious that although (many) certain slides are clearly in focus on a light box using a loupe, they are not in focus with a dedicated slide scanner. Also, if a slide is very dark, in other words, badly underexposed, there is not much to be done to rescue it from a scan, even with photoshop. Then I read on this forum about photographing slides. I bought a Nikon ES-2 at my local camera store for under $100, a step down ring to mate it to my lens size, and used several “close up filters” which are not filters at all, but screw in macro adapters. I can fill the frame with the slide (proportions slightly off, not much). I adjust exposure in camera for the badly underexposed slides, and they turn out far better than I ever thought possible. And everything is in focus. So for under $200, IF you have a lens that will work for this, you can be in business. And instead of scanning 4 slides every 10 minutes, I can shoot probably 10 or more slides in 10 minutes with much better result. Tip, the first step is to see how close your lenses will focus (approximate) before you decide to go this way. If you want to know my combo, I am happy to share. JimR.

I have had an Epson V550 for six years and am very happy with it. It does slides, 35mm negatives and photos. Problem is, if you buy it at Amazon, the price has skyrocketed from the price I paid, $149.99, to $693.92. Amazon appears to no longer have the best deal in town. I recently had to replace my Canon printer and found out they're like toilet paper was three months ago. I scoured the local stores for two weeks, and nobody had the printer I wanted. But Amazon had it for about $50 more than the local asking prices. I finally broke down and bought it from Amazon. Bottom line, whatever you decide to buy, you might want to shop around.