I dunno, paying for shipment of lead always seemed counter to my goal of shooting as cheaply as possible. The exception is clean tin for alloying.

I go to local metal salvage shops, tire emporiums, and plumbers for old lead shower pans and roof flue collars. The salvage shops almost never fail to have drumfulls of wws and sometimes lino to pick through. I often find lots of huge ones that must have come off of 18-wheelers. These are really sweet as there's way less clips to mess with.

Even better is when I accumulate a bucket of range-salvage brass and stuff that's reached it's reloading limit. I come away with several lbs of lead for every 1 of brass.