Did you check Ebay? Billet aluminum are available, two for less than $30 shipped free. Also I saw some used for sale. Different colors if you want to go that route, and some that are lazer engraved with the caliber you set it up for.
I had one that I don't use too much anymore, but after seeing the price on Ebay, I doubt those prices can be beat, especially with shipping that would cost at least $8.