I am mainly looking for some good .30 cans, prefer new but used in good condition would be OK. Everything I have found equals or exceeds the .50 prices when shipped.
I have picked up a few .50s at Rural King, they currently have new ones on sale for $13.
Check Widners, i think i saw a deal posted on Slickguns for $8.00 each, don't remember the shipping but i think it was a good deal. I prefer the .50 cal cans but this seemed like a good deal to me.
I like the smaller cans too and they are hard to find so I started going with the plastic ones a few years ago and had good luck with them. You can get around 500 rounds of 40S&W in one or 500 223. Just a thought.
A few months ago, I ordered a bunch from a1bargainson eBay. I was getting new BLACKHAWK .50's for $15.99 SHIPPED and new BLACKHAWK .30's for $14.99 SHIPPED. May want to contact them and see if they have more in stock and see if they'll honor their past prices.
I've picked up .50cal cans at Bradis II from time to time. Usually they are in good shape and reasonably priced. Sorry can't remember what I paid the last time I got some but I'm sure it was under $15.