Late to the conversation but will add Craigslist, and Facebook market place as online sources. Picked up 150#s of 70/30 body solder on Craigslist for $50. Friend of mine who’s on Facebook (I’m not) sent me info from an add for lead. I called and picked up 265#s Tanacorp Magnum ingots $165.
Ive found lead in lots of different ways. Mostly just by keeping an eye out for it and networking. Rotometals is great should you find a stash of soft lead. They sell high antimony content lead you can add and bring up hardness. Old pewter wares are excellent sources of tin. Easy to find cheap at thrift stores, flea markets, antique shops, garage sales etc...
Good luck!
