BalanceFrom Puzzle Exercise Mat Interlocking Tiles (Various Colors)
+ Free Store Pickup
Walmart.com has BalanceFrom Puzzle Exercise Mat Interlocking Tiles (Various Colors) on sale for $17.16 - $1.25 (store pickup discount) = $15.91. Free store pickup must be selected for discount to be applied at checkout. Thanks sampleboy
Amazon has BalanceFrom Puzzle Exercise Mat with EVA Foam Interlocking Tiles (Six 24x24x0.5" Tiles, Black, Covers 24 Square Feet) for $15.19 after you clip the $1.25 coupon. This is highly rated product (over 4 stars and 752 customer reviews) and includes the edging as well.
Shipping is free for prime members or if you spend over $25.