I believe it has 5mm thick aluminum disc bottom, which makes it a good pick already.

I saw a stock pot tonight that was copper on the outside and stainless on the inside. Is copper a good choice too?
Thanks!

I think the copper is 2mm~2.5mm thick, which meets the minimum requirement for a quality copper cookware piece. I didn't pick it up because it's too small for me. Besides, with this price I can buy a much larger enamel on cast iron pot nowadays...
If you have the money, then go get it, it's a good piece, and price is much lower than on amazon.com