Marketplace
There's a long-running deal on these copies of Dropmix on Groupon for $34 + $9.95 shipping (link at end of post) and I bought one recently.
I ordered it on the 2nd when it finally arrived today (20th). While the box was triple-wrapped in bubble wrap, then wrapped again in black plastic, the box was still moderately damaged (which didn't bother me much) and worse of all, its seals already cut - which seemed to be a customer-returned box with the cards unopened and the board in perfect condition. While it might seem minor, it's a shame that the Groupon page lacked details, where I (and the average Joe) presumed I was getting was a brand new copy and instead got this.
I've already sent an email to Groupon and see what will happen.
Something to be wary of if the above bothers you.
You might just be unlucky
Someone returned it tricking their supplier and they sent it to you not knowing it was already opened