I'd leave the electronics alone, that and car batteries.
I frequent local scrap yards and sometimes come out OK, other times nothing. Most times I get some sort of alloyed lead. A couple of scrap yards won't even sell to individuals, they just buy it.
I finally got sick and tired of hunting all over the place for dribs and drabs, and bought a pallet from Rotometals. Kinda expensive, but a 1000 pound pallet came out to 1.72$ a pound shipped to my door. The 100 pound ingots are not too much trouble to handle, but not easy either. Anyway, I'm set for pure lead and it's easy to alloy up with tin and wheel weight lead. A hardness tester is a nice tool to have as well.
My 20-1 alloy that I use most often with nothing but lead tin mix, with 260 grain 45's cost .095 cents a round. Also not taking into account time and electricity to cast my own. Moulds do wear out over time, and electricity cost as well, but a cent a round should more than pay for that, plus you need to lube the bullet. I use alox, home made smokeless, and homemade and pearl lube 2 black powder lube, depending on bullet and what I'm going to be doing with it. Figure another cent or so for that.
So say it's costing me 12 cent a cast and lubed 260 grain bullet cast from pure 20-1 alloy. Now, that's for the 45 colt, my 45 acp gets a mix of pure lead and wheel weight and scrap lead to bring the hardness up just a bit, so that brings the price down a bit. I use as much scrap as I can, it's just hard to find good cheap scrap down here.
For my conicals I cast from pure lead, at 1.72$ a pound, a 200 grain conical comes out to .05 cents a round, not counting mould wear and tear, electricity, and lube.
Of course there's a bit of work in chopping the 100 pound ingots into manageable pieces, but I stick then in the forging press with a hack and chop them up. And I don't have to hunt the countryside looking for suitable lead.