I have half a dozen all the way up to two 34600 (10+ gpm) bilge pumps and get my parts off Ebay. A set of valves can run from $35.00 to $250.00 for our big ones, so keep an eye out and grab them up when you can. It is also nice to have a spare diaphragm. Boating shops are not the cheapest for these parts.
I buy up any of these pumps I can find and one kind person on the forum sent me one he no longer wanted. I got a 34600 (discontinued, but absolutely the best bilge pump if one can't use a submersible, $500.00+) for $10.00 including one of those nice expensive float switches, because his yard said the 34600 was out dated equipment (he believed them!) and he wanted to get rid of it as such. After the sale, I thanked him profusely for the pump and switch, as he had no idea what it was worth to me.
