What about ebay? Kilts come up second hand there all the time and if you arent fussy about colour, you might be able to get them all within your budget by looking for last minute finishing auctions.

As they say in costuming, you can pick any two out of I want it cheap, I want it fast, and I want it right. You can make decent cheap kilts, but it takes time and effort, you can also buy cheap kilts fast if you go second hand and arent overly fussy