Actually upgrade, and get the "Dri-Core" stuff -- it has a dimpled 1/4" thick plastic base that allows water to flow underneath, and has risers/levelers allowing you to compensate for an uneven floor. Have this in my 300 sq ft basement and it makes it nice and WARM (no more exposed cold concrete) and nice and level. You can also do it on the cheap with 4x8 sheets of tongue and groove OSB and then glue on your own "Platon" dimpled layer, usually used for waterproofing the outside foundation.

You're right, I saw the stack and didn't look at the overturned one. I bought mine about 8 yrs ago when they were $4.49 a square at Menards, saw they increased shortly afterwards to $6 something (when OSB skyrocketed). Mine had the circles on them , i see yours has the newer starburst rectangle patterns.

The Platon brand actually does sell their stuff for underlayment explicitly. No glue needed, but they want you to screw the OSB then through it into the concrete. I think you could just contact cement it on the OSB like how Dri-Core is made.

http://www.certainteed.com/resources/Platon%20Flooring%20Brochure%2040-98-02D.pdf