I've smelted some brass, aluminum, and silver. I made our wedding bands. I ruined a few silver dollars and silver quarters practicing but I didn't want a cheap chinese made ring.
if there was a place to find cheap silver id be on it lol
you can always strip computer parts and melt them into ingots to sell to scrapped who can purify the metals out of them. but its a hobby
a buddy of mine made a furnace out of a waste oil burner and a 55 gallon steel drum for copper shot (copper melts under 2000F and steel melts around 2500F i think)