Once a year the local Rockler has the Sorby rep in and offers a 20% discount that day only. I happened to order a 20 tpi set last week. If you have a local store you might check as the Sorby rep is touring now. I've also seen Mark St. Leger demo his and he makes it look pretty easy. Any way you go, there is a pretty steep learning curve and the right wood makes a lot of difference. One of the reasons you see so many people do the threads as insets a opposed to cutting threads directly in the vessel. If money is no objet and you don't have an objection to machining over hand cutting, I'd also look at a threading jig like the Baxter Thread Master ($500) or the lathe jigs.com ($300). Personally I'm working on the learning curve a bit before investing that much.