20:1 from Buffalo Arms.  Shipped in Flat Rate boxes.  I just need to warn the Postal lady when I place an order.  Just back the truck up to the garage door and dump them on the driveway.
She’s cool.

I used to buy from Rotometals packed in flat rate boxes it was a pretty good deal.

20:1 and 10:1 covers 80% of my shooting needs, plus some really soft 30:1 and 40:1 for .22's. My bad old self used to live by wheelweights and type metal, that's behind me since I discovered binary alloy nirvana.

I buy from the little guy who sits on the half ton of lead and maybe 150 pounds of tin out in my shed. I give him beer and a bowl of gruel and he lets me take some of my heavy metal.

(I was fortunate in lucking into several serious quantities of tin and known tin:lead concoctions over the years. I should capitalize on the tin, seeing how crazy valuable it's gotten, but then I wouldn't sleep well at night!)

If they still have them where you are you might try a junk/recycle yard.  It's been 27-28 years ago but I bought 500 lbs. of salvaged X-ray room sheet lead for 20 cents a lb.  Still have a little left.  Granted it won't be near that cheap but it is pure lead.

Other than that nearly all my lead was free, back then.  Plumbers lead, lead plumbing pipes from remodels, roof flashing, wheel weights were saved for me by the two tire shops I did the electrical work for and people would just give me lead they found or had on a shelf for years.  A couple years ago a friend gave me about 30 lbs. and once, at our electrical supply house, a complete stranger was in their trying to give away about 10 lbs.  I offered to take it and he gave it to me.  You just never know.

About the only reason for a sane person to be on Facebook is so they can use Marketplace. In my area there is always Lead, lino and pewter(tin) for sale and if a person watches they often come up at bargain prices and always some for sale at high prices. That being said there must be areas where there isn't much for sale, otherwise I don't understand why anyone would pay the prices asked by the metals suppliers?