Me and the neighbor split a half bushel of raw oysters (30 pounds) It cost 40$. Gotta splurge, sometimes!
There were some monsters in it, about 20% were open, throw those away. Get a flathead screwdriver, crack them at the hinge, if it is hard to crack and still full of briney water, good to go! Easy to cut your hand if you don't watch it!
He went to get them. Next time I will go and I will tell the seafood guy "these are expensive enough as it is, I don't want a single, open oyster!"
But SOOOO good, stand in the back yard over a table and devour the sack and a bunch of beer!