There are a lot of people that use EVA foam to make Cosplay costumes, particularly light weight armor. I often thought that this stuff would make some cool looking robot parts as well. I saw that one of the ROBOMO users used it to build a cool looking robot head.
So I did some research on the web, and found out that Harbor Freight sells an “Anti-fatigue floor mat” made out of the same stuff. One package contains 4 roughly 24" X 24" pieces.
It was on sale today (11-6-2020) for only $6.99 per pack . I think that this is a really good price.
Also, Hobby Lobby, is selling their hobby foam ( EVA) at 40% off today.
Both of the stores that I went to are in the Crestwood, Kirkwood area.