Two years ago a 5 yard made to measure James Morrison kilt by Heritage of Scotland was to buy from £151. On most tartans there was an additional charge, but in the most common tartans £151 would do.
Today the James Morrison brand has disappeared but Heritage of Scotland are still offering five yard kilts made to measure. Now, however, prices start at £200. But you can hardly find a tartan without an additional charge. At least I have not been able to. They are £30 or far more extra.
Companies are free to take the price for their products they want to and to increase prices as much as they want to. But I find it rather questionable if a “from” price is pure theory.