I'm paying no more than $10 for a 5 gallon bucket from the tire stores. I'm still pulling 70-80 lbs of lead from a bucket. About half stick-on, which is soft lead, and about half clip-on which is harder lead.
For soft lead I also hit the local scrap yard and get soft lead scrap for $0.70-$0.80 a lb. There's also Roto Metals if one wants to go that way. If I were to want a large amount....say a ton, I'd just go smelter direct for around $1.25 a lb for alloyed lead.