Aldi.
$4.50/ lb for shrimp
$3/lb for Talapia
$5/lb salmon
Scallops are $6-8 /lb random grocery stores.
I'm feeding around the same 2lb per day. Making the homemade food seems to be more efficient. Seems to fill them up faster. Wrecks the water, but if your filtrations up to snuff it's no biggie. I use a bunch of stuff in it..... Fishdog suggested some greens like spinage and some other crazy stuff so been using that, tossin lottts of flake food in there. Pellets of misc kinds, salmon, talapia, shrimp, scallops, whatever works. Usually use the homemade stuff 2-3 times a week and off days are 50/50 shrimp and some sort of fish.
Seems most of the smaller chain type grocery stores will deal if you talk to the right guy. Explain what you need a month and they can get you odd stuff too if they know you'll be takin it. Fairway and Hyvee are examples, not sure if you got them out there, but if not likely there's something similar. Aldi is a walmart type cheap grocery store. Hard to beat them on shrimp.
Smelt I can't even get here anymore.