I believe the Soft Tiles are 5/8" thick. If you're on a budget and don't mind using 3/8" thick tiles, you can save a ton by getting near-identical tiles through one of the Amazon.com sellers such as:
We Sell Mats
I've used these for a practice field and they have the same smooth-side on the other side of the tiles.
$89.99 beats the heck out of Vex's $189.99!