Magic is a most rare and powerful force in Ravenloft. It is twice as rare as in other worlds, and rarer still for the low populations of the demi-plane of dread. That makes magical items and spells twice as valuble as before, though often magic can be hard to sell - many items in ravenloft carry curses or don't function correctly as intended.
Then there is always the chance of attracting the attention of the dark powers...