Big Joe,
There is no such thing as cheap 410 ammo. The cheapest I have gotten in the last few years was some Estate shells for about 50 bucks for 10 boxes. Loading 410's is of course much cheaper...money wise.. but not cheaper work wise. 410's are a bear to load...and I load a bunch of them..but I have a very expensive loader to do it on. The best loader you can get to load 410's is a Mec 600 Jr. They will load about 200 shells an hour...after becoming used to the loader and the idiosyncrasies of it. You can sometimes find a good used one for 50 bucks or less. Isold my last for 40. I just got a fellow a half case of 3" 410 shells and they cost 85 bucks...terrible price....8.50 a box..horrible...and the darn thing is so hard to hit things with too. Luck man