In my area (Alberta, Canada), I found it in Costco and Canadian Tire. Costco was only $22 for eight 24"x24" tiles (just enough for my floor), so I bought 2 packs so I had lots for replacements. I love my local Canadian Tire store, but they were double the cost.
Yes, I anticipate dirt and grit getting into the puzzle joints, but it shouldn't be too hard to take it up and clean. It's the price you pay for being cheap
. I got a quick install, but will need to spend some time with upkeep.
Venture Products: Best Step - Comfort Flooring