Interesting thread.
There are a couple of glaring errors in your calculations that I'd like to mention.

You listed my price in Canadian ($150.00 CDN is $115.00 USD) and USA kilts ($110.00) in US dollars. Most of the clever lads here would catch that but just in case ...

It takes me a day to make a four yard kilt. I used to do two a day but as you've heard Jimmy tell you, my quality has gone way up since I started making kilts and that extra care takes time.

I'm not going to get into details of what I pay for fabric, labour, or any other aspect of my business, but most of the mistakes in calculations were balanced with opposing mistakes. (ex: too low fabric costs balanced by double wide fabric.)

I like the gist of the thread; you get what you pay for. The lowest cost casual kilts on the market today are from offshore factories. The only way to lower that cost is to find a sweatshop in an even more desperate part of the world.
Casual kilt quality comes with proper construction, good fabric, and custom fitting. There will never be a $50.00 quality casual kilt.