My 870 Express combo (28" ventrib and 20" IC with rifle sights) only cost $330 at a Wally World in Maryland. Walmart also has a 26" Ventrib and 20" Rifled barrel combo kit for like $345, but it has wood instead of synthetic. You might have to call around to find a store with one in stock, or just special order it from your local store (wont cost you anything extra, but it takes about a week to 10 days to arrive).
Kharn