Bought six, live, softshell lobsters for about $40, cooked them, immediately plunged them into ice water, cleaned & picked the meat... made 5 hot dog bun-size lobster rolls... Approximate cost of each FRESH lobster roll = less than $9.
Then I made lobster stew with the remaining bits and pieces.
fwiw, I believe the 3.99 ones are going to be softshells -- they don't last too long in those tanks because they are too delicate.