Never dealt with MM directly and was not aware that that was an option from their website.

Scotweb has the same Fraser (red) fabric in 11oz MM poly-viscose at $12.55US per yard double width, as they are currently having a 20% off tartan fabric sale through April 1. But, unless you are ordering a significant length the shipping is likely to kill the deal---over a certain amount and shipping option becomes free for the slow surface route.

They also have good prices on the 16oz wool ($25US for DW yard) and 13oz wool ($26US for DW yard) if wool would be preferable for your purposes.