I've picked up the tools over time from Ebay mostly. Like Miller said, they were cheaper a few years ago in both shipping and costs. The 12 gauge ones are still low in price. Bidding on 20 ga. is higher. I've yet to see .410 or 28 ga. on Ebay US. Ebay.fr will have them show up from time to time. There was a Frenchman who liquidated his collection of hundreds of tools. I bought directly from him as well. Interesting that the man neither hunted nor shot but collected the tools for a long period. He was a reliable source of subgauge crimpers for a few turkey hunters.
Miller, I've recently acquired (not here yet) a 16 ga. wad compressor that is a plunger inside a spring loaded metal tube that fits inside the hull. The wooden plunger is depressed releasing the wad inside the hull. I'll post a photo when it arrives. Gil