I got a weighted vest and blanket for dd who is 5 and she does not use either. TBH she probably does not need them as that side of sensory behaviour has improved. They were expensive - £120 for blanket and £60 for vest. I was thinking about selling them if it works out she does not need them.
Problem is don't know how much demand there is and how much to put them for sale for. Do you think ebay would be a good place.