Blind people aren't going to collect anything that doesn't interest them, unless it's for economic reasons. People tend to collect things that interest them.

For a blind person (and speaking as a sighted person, though one who knows a blind person very well), blind people are going to be attracted to physical form that can be perceived by touching, as well as function. Visual attractiveness will do nothing for a blind person (unless the person has some sight and can actually see the beauty). On the other hand, textures that might matter little to most sighted people might be very interesting to blind people, since they relate to the world through touch so much. How the object sounds as you use it might be a part of the experience as well.

I don't think sculpture would be off the table - sculpture can be touched. But blind people probably wouldn't care much for paintings, unless they were trying to buy them for monetary gain later.

As an example of this, I have a nice skeleton watch that looks amazing, but my blind friend is far more interested in my $25 Soviet Raketa watch, even though it's very plain-looking, because she thinks the sound of the movement is more interesting.