I purchased 20 pounds from this place, seems to be quality product
LEAD INGOTS | Seabrook Fishing Sinkers
They have a 25% off sale going which is just over $2 per pound with free shipping on 44 pounds. Only close price is Rotometals for a half pig or a whole pig.
I've also bought from a seller on muzzleloading forums, melted pipe and sheet which passed the 6B pencil test for soft lead.
With the size of the projectiles many of us cast, the pounds go fast! 7000 grains per pound or just shy of 22 rounds at 320 grains, or 40 of 177gr round ball (50 cal). The last time I cast I did just over 100 Lee REAL 50cal in 250gr and just over 100 in the 320gr sizes. A few over 50 pours each mold to make sure I could toss a few if needed and end with at least 100 each (over 8 pounds total). I need to get out and do some 45 ammo too.