In general, I'd expect to pay between $400 - $800 for an 8 yard kilt made in genuine 100% wool Scottish tartan. Within that range what you pay will depend on if it is made from light, medium or heavy weight wool, whether it is a stock tartan or a custom weave, what mill wove the cloth, what kilt maker is making the kilt, and whether the kilt is hand sewn, machine sewn, or a combination.

For a "casual" kilt, made from 100% wool Scottish Tartan, I'd expect to spend between $250 and $350, again depending on the weight of the wool, the specific maker, etc. Most all "casual" kilts will be machine sewn.

If you see a kilt for less than that (unless it is a good deal on a second-hand kilt), expect it to be made from a non-wool cloth, machine sewn, and probably imported from Asia.

Another telling factor is that most quality kilts are not going to be available to purchase off the rack at a Highland Games, but will be tailor made to your measurements from the tartan of your choice. The ones you see at many festival being sold off the rack again tend to be the cheaper Asian imports.