Well, that and a shop to do it, depending on the shop. They charge plenty of moneyz for their time, so anything you have 'em do that takes a lot of it also takes a lot of $$, which is why, imo, milling a solid chainring would be a decent compromise. Course, it may be it wouldn't be much more expensive to do it (design and gear) from a blank with a suitable CNC/machine tooling, someone who has had recent work done at an up to date shop should be able to help.