Hello drrifted, welcome to The Acaeum!
Those are two wonderful pieces of TSR history.
As
Foul mentioned, these are both exceedingly rare and very much in demand.
There's not a lot of sales history on either of them, but it wouldn't be surprising if the chess set would sell at auction for $4,000-4,500. The chalice is equally as rare as the chess set, but has sold for less at auction. It would likely sell at auction for $1,000-1,500. It's really hard to say, though, since there haven't been a lot of sales in recent years, and prices have gone up considerably for rare TSR collectibles.
I know these likely have some sentimental value, but if you are considering selling them, your best bet is to do so at auction, preferably on eBay, or on one of the better-known Facebook D&D groups. If you are thinking of going this route, it would be best to post an announcement in The Acaeum Classifieds and on one or more of the D&D-related Facebook groups. Would recommend listing them with a low starting price, and no reserve, and they will sell for the best price. Include lots of pictures too.
