If you need any more, I got my diamond hole saws cheap from a guy on ebay from somewhere in Asia. The name of his store is "THK Diamond Tools". And the seller is "lau***" (yes, those are astericks, not some RC foul language modifier).
I think that I can post those ebay details since I didn't post an actual link to an auction or something.
Also, I should comment that you can get one of his hole saws for about $10 - $15 landed. I have two of the same size (some 1.5" heavy duty bulkhead off of aquaticeco.com) and can donate one to the equipment program of the club. Of course, someday it will wear out....