An inventive (and cheap) sub I know made a homemade vacuum pump out of, get this, one of those Hefty bag kits that were designed to remove all the air from the bags and retard food spoilage. He cut the receptacle off one of the bags, and taped it onto a uncapped water bottle he got at the dollar store. Then he connects the pump and he is in business. Total cost of this pump? About $5.
the bag kits look in the food storage section of you local grocery store. the is a new food storage back on the market that has a vac pump that pulls all the air out of the bag so the frozen food i vac sealed!