For in-store pickup only, Walmart offers the Gold's Gym High-Impact Flooring 6-Pack, model no. MT-GG1206-2IS, for $18.97. That's the lowest price we could find by $13, although we saw it for $7 less in November. Each piece measures 24" x 24" x .5". The 6-pack comes with edges for a finished look.

Of note: it's also available shipped for $18.90 plus $4.97 for shipping.