Sun Plastics 900 Passaic Ave. Also has custom loaded cassette tape of various lengths in colored shells. One of the cheapest around in black and std colors. Prices for mastering, processing are average to above average. Pressing is the lowest I've seen.
Many packages exist and are low priced.
Keep in mind it deals with large volumes and is consistancy can be low in quality of record and customer support. Low cost of pressing also translates into lower thickness of record. This company has plenty of satisfied customers and plenty of unsatisfied customers. Decent color selection, too. My band has done 2 singles with them, one black and one blue.