There are three chain ethic supermarkets in southern California near where I live: Ranch 99, Vallarta, and Jons. Meats, seafood, spices, seasonal fruits, and odd-things-to-try-out, etc., are very inexpensive here. At the latter two places I can buy a lot of whole tilapia for a very good price. The following is a relatively generic, but simple way to steam tilapia. I'd imagine that this preparation style is common to asian households.
1 whole tilapia, thawed and cleaned
2 stalks green onions, sliced
1-2 slices of peeled ginger, thinly sliced
1 tbsp Chinese cooking wine (red or white, doesn't matter)
Before the fish is steamed, you need to make two slits on each side of the fish (through the flesh to the bone but not cutting through the fish, this helps it steam evenly and cook faster). Pour the wine over the fish and place the ginger and green onions on top.
The average whole tilapia will be under a pound, total cooking time is about 20 minutes. This seems like a long time, especially for fish, but I skip the process where you let a steamer come up to temperature then put the fish in. The flesh of the fish should be of a white-ish color when fully cooked. Promptly remove from heat and serve.
Whole fish pairs with steamed rice (brown, white, or "wild"). It goes pleasantly with a dry riesling wine, like Columbia Crest (which you can usually get from Trader Joe's).
I eat this with a sauce that has equal parts rice wine vinegar and light soy sauce.