I second the advice about color-corrected lightboxes and good quality loupes. I have a simple flourescent lightbox which I bought when I ventured into slides years ago, and the difference with my current color-corrected Cabin panel now is quite apparent ... the non-corrected lightbox will give a bluish cast.
I also bought a cheap Kaiser loupe when I started ... used it all of 2-3 times before I got dizzy. Easiest path to spoil your eyesight. I then bought a Nikon, still not quite there, though a major improvement, and now I'm on a Cabin loupe that's superb. Unfortunately it doesn't seem to be sold anymore at Cathay where I bought it ... IIRC it was around $120 or so ... I think it's 5X.
Just bring a few good slides, with good detail and colors, down to Cathay, Ruby or any of the other shops you can get to, and just test things out. Make note of how good they are, and how much they cost, and I'm sure you can find something that'll fit in your budget. You just gotta be careful ... I made the "mistake" of looking through a 6X Schneider loupe at Cathay ($300+, I think), and nearly handed my credit card over :bsmilie: ... it was sooo nice ...