I've ordered more dies from Fabric Hut on Amazon, plus Ritz Camera of all places. We're retired military and they have a store with Aafes. They were the cheapest I have found so far.
Also Jhlittle has some, plus Shoppers Rule where you can name you own price. Whenever I'm looking for a specific one I check as many places as I can and do price match including shipping. Sometimes if the die is cheap, the shipping can be outrageous.. so just check around.