If you won't be wood burning, you can get by with the aluminium cone. Trail Designs doesn't list the Fire Pot as an option so you might have to order a custom cone, which adds $15 to the cost, bringing it to $49.95. However, since they have already got a design for this pot and you don't need the stove or a caddy, you may be able to get them to reduce the price a little.
According to the website, they're away on vacation at the moment, but they're normally very good about responding to emails IME. I suggest you write to them and ask.