I’ve bought several proof sets at antique stores for melt value (at the time). I considered the penny and nickel as a free bonus. Oh, and melt value was between $22 and $26 when I bought them all.
I cleaned out the “junk” at an antique mall in Kentucky because he was still valuing it at about $26 melt value while the current price was in the mid-$30 range. I wish I had cleaned it all out. It was only about $450 worth that I actually got, and another $300 or so left, but still...
My brags are getting 1/2 ton of lead (mostly precast as bullets, with the ideal alloy) for 1/4 of the lead spot price, two years ago. And getting hundreds of pounds of copper, ad once fired cartridge casings in popular calibers, for about 20% of melt value, and out a year ago, at a garage sale).