hmmm.... I'm not sure the Tartan Police have much sway over here..... although, I was told by our bus driver a few years back that there are more Scots living in Texas than in Scotland... of course, Scots are much like my ancestors, the Irish..... "never let the truth get in the way of a good story".....
I think Irish wore kilts some, as well, but it's the Scots that everyone thinks of when discussing kilts.
Genuine kilts in Edinburgh shops are not cheap.... the cheapest I saw were uncomfortably close to $1000, and went up quite a ways from there.