I'm creating a game where I wanted to use something similar to the Invader Mat, but I didn't want the mats to be flimsy card stock, so I created an SVG cut pattern for a Custom Medium Punchout that provides two Invader Mat shaped cutouts per sheet.
I wanted the hex size to be large enough that people could use standard sized miniatures (D&D, d20 Open SRD, etc.), so I increased the size of the pattern to the largest that could fit (.9" hex size).
I created a test game with no other products but this one added, and added 4 slugs (a full sheet) and the cost came to just a slight bit over $10. 8 invader mat punchouts with the hex at 1" in size per space seems a reasonable price to me
I wanted to share this with the community, since it really should be a standard option with TGC, but isn't.