TBH, there's not that much seaglass around like there used to be. In St. Martin I was on a beach and could have filled a gallon sack in an hour. It was crazy and beautiful.
Also, at some old school very tacky shell shops on the side of the road in Florida beach towns...Some of those shell shops have old driftwood for sale. We have a place in St. Augustine and there's a truck that drives down the beach most mornings and a guy throws driftwood into his truck after the tides been out, usually after a big storm. I never understood what he did with it but people do all kinds of things....Building furniture with it is popular and selling it to the tacky shell shops is another...