Fish on Bleeker Street does half a dozen Blue Points with a glass of house wine (or beer I believe) - for $8!!!
I've only been once because my Hubby hates seafood, - but the night I went the oysters were fresh and delicious - the house wine - a chardonnay - I felt did not pair well at all with the oysters....but for the price - you can't complain...by the 2nd round it didn't matter too much!!
For clams you can go to the Chinese seafood buffet in the Loemans Center Sheepshead Bay in Brooklyn. They have the clams iced on the buffet already opened. Eat as many as you wish, not to mention all the other food for about $15. They do not have Tabasco sauce so I would bring my own. People would lurk around the spot for steamed crab legs and clear them out as soon as they were placed. Had a pretty decent blue crab in scallion too. Peel and eat shrimp were hit or miss. Used to be a Friday night after work tradition with a buddy Doc when I worked in Brooklyn.
Definitely big bang for low bucks.