IF you really want to make ingots check out this site. http://www.backyardmetalcasting.com/index.html He shows the cheapest way to get into a forge. You have the different kind of fuels to choose from.

I do cast my Al and Cu into ingots. The cost is free for me since I do sand-casting. Still learning on the metallurgy of smelting for purity.

I have been visited by local sheriffs that know I melt metal, twice. Both times after scrap was stolen in the area.