Yamaha has 4 ranges:
"Student" - 21, 23, 25, 275, 280
"Intermediate" - 32 (called 52 in some countries), 475, 480
"Professional" - 62
"Custom" - 82, 82Z, 855, 875, 875EX
However, the Yamaha "student" models are very well made - much better than some Chinese saxophones labelled "professional". A good used 2xx Yamaha can be very good value, and great fun to play.
I have heard (though I'm not sure about this) that the 32's had the same body as the more expensive 62, but without the fancy engraving, and with slightly simpler keywork. That should mean that they sound like the more expensive pro model.
Most people reckon that the 62's are very good horns, especially the early ones.
The Custom ones were a later, more expensive, addition to the lineup.
The very early models had the Yamaha name stencilled on the side of the bell in a dark red-ish sort of colour (the so-called "Purple Logo" models). Later ones were stamped. In the usual "the old ones are the best" fashion among saxophone geeks, the Purple Logo ones are considered by some to be superior, and will therefore probably cost more.
Similarly, the early 2x instruments were made in Japan, and later ones (275, 280) were made in Indonesia. Some people say that the Japanese-made ones are better.