Rings are a bit different then, say, a chain would be. I highly recommend not going 18k or higher on a ring. My ring is white gold. So gold mixed with Platinum. To get it to melt it takes a hell of a lot more heat and time then what normal gold takes. So long that when I was trying to melt the left over scrap into a ball I thought I had just created a crucible with a good chunk of gold stuck to the bottom. Yes I was using an OXY torch. Because your hands are always smashing, rubbing, touching, what ever else, it gets a lot more wear then other jewelry. Girls to. And it will show a lot quicker in how fast you lose the nice, out of the box shine. In the end, that is what your looking for. It will never wear away in your life time even at 24k, unless its a reallllllly thin ring. Most gold in NZ is 92-98% pure. So if you have 10 grams. You should end up with 9 after refining. Ask the jeweler who is making your rings for you if you get the keep the scraps. If they say no. Your getting ripped of on everything. And by going 14k you can maybe make 2 rings, and still be able to stand straight.
I used TP goldsmith in Hoki. The lady was really nice. Worked with us with everything as we had 2 different types of gold. One rose, one white for our rings. We got all the scraps, and was by far the cheapest, AND BEST. We talked to jewelers from Auckland to Invercargill, in person. 90% are not even jewelers, 5% are unskilled rip offs, and the other 4% are great jewelers, Just over charge. Arrowtown was double what I paid. In the end its up to you but I know TP jewelers makes great rings and if you are willing, she will even teach you how to make them if she has time.