My needs are slightly different due to the number of cages we have here in rescue, but I can say that I won't pay for a cage set with a fleece vine. NONE of the gliders here use them. They are cute to look at, but here we are all about function.
I want cage sets to have 2 pouches, 2 corner hammocks and one hammock or bridge. I want the pieces to be a nice size, not small like many I receive. I want them to hold up to multiple washings and to a wide variety of glider personalities and colony sizes. Please double stitch all tabs inside.
In terms of what people want and what they look for safety wise, you might check out the SUGAR Group's 2012 report on either TSG's website or on the FB page. Several hundred owners were surveyed and their answers to questions of interest to vendors are a part of that report. ;)