Gold leaf is an interesting material. Some of the architectural structures that are covered in gold leaf look like they contain lots of gold. In reality, it might amount to a couple tens of ounces due to how amazingly thing gold can be rolled.
While I haven't melted down gold, I've made a couple rings from silver via lost wax casting. I actually used 1 ounce American Silver Eagles. No reason Gold Eagles or Canadian Maple Leafs (if you need 24k) couldn't serve as a source for your project. Cheaper though would be to simply melt gold scrap which can usually be had for less than spot.