A 45 pound box with freight is $109.99 https://www.rotometals.com/mono-foun...-balance-lead/
Works out to around $2.45 a pound delivered so not that bad on price. They say quantity is limited.
They also have a 1000 lb. pallet for sale but... that amount is a little spendy but gets the price down to around $2 a pound. I wouldn't sell it that cheap generally speaking. Of course I don't have 1000 lbs. to sell either.
Thought this might be of interest to the folks posting about getting alloys or wondering about what to mix in as a sweetener. At 8 - 14 percent tin and 20 - 26 percent antimony this would be a pretty good sweetener, especially for a quantity of plain lead such as flashing.