I had an add on the EE for some i was offered new boxes of it remington stuff for 80-90$a box. But ended up buying 200 reloads to pull apart for bullets, powder and primed cases for 100$.
Ive also bought a few older boxes of winX and imperial from a guy on cgn at 20$ a box
You can also use 32-20 brass and run them through your dies with a good wax lube and not lose very many at all. You can buy them pretty cheap from rustywood
I shoot them in a single shot Lee Metford i rebarrel with a win92 barrel