Unfortunately, kilt jackets are still specialty items and are not mass produced like regular cut jackets, so you're going to have to pay for that. You might get lucky and find one in your sale for sale somewhere. As far as I know, there aren't even any cheap Pakistani made jackets.

Unless kilt wearing becomes more widespread and thus the need for jackets cut for kilts increases, the situation will remain the same.

I have found that since kilt jackets are so much more expensive, I go ahead and get made to measure jackets. They fit me much better and are only a little more expensive.