Picked up from a store for 20 and some change hits very smooth realy thick glass for 20 dollar piece to !
Collaborations are when multiple artists get together to make a piece, so they make a (Collab) of their art work in one piece. it's usually a scientific glass blower + a heady/ line worker, or some sculptures will get together. These often have a high retail price, since it has multiple artist's work in a single piece, and they are usually a limited edition #1 of 4 etc. look up some artists Collab pieces, and you will see.