I found this on the web sites:
Martelli Mats 26x38" = $129.99 (!!!!!)
Olfa Mats 24x36" = $53.49
Fiskars Mats 24x36" = $43.05
From the Fiskars site it appears they are no longer making the gray mats. The new ones apparently have a self-healing "coating". They address the problem of this coating's odor:
"The odor is caused by the self-healing materials and sometimes the odor can be very strong. There are some tricks to get the odor out:
Wash the mat with a mild soap and let it air out. This may take a few weeks
Spray Febreeze on the mat and let it air out.
Store the mat in a sealed container with some coffee beans or some crumpled up newspaper. Those two items help absorb any odor."
In the past, quite long ago, Fiskars was responsive to complaints about their first rotary cutter design which was unsafe, and within a year they had included a guard on it. Perhaps they've redesigned their mats as well. I've felt forever that those gray mats were the fastest 'dulling-makers' of any blade on the market. I'd be willing to give the new mat a try, perhaps, but I do so rely on my over 20 year old Olfa green mats!
Jan in VA