I have had good luck with ebay uk. I have picked up a surplus blackwatch for a lot less than it would cost on ebay us. The only thing is shipping, it cost more to ship than the kilt ( approx $50 total). If they ship it Royal mail listed as used clothing it usually does not have any import tax. I am a 28" waist so I can understand your problem. As long as you don't need it this week there will be one show up within 2 weeks.

Good Luck, Mike