This deal looks a bit complex but the price is awesome. It's apparently a Russian region game key (ironically, based on the description, the available languages don't include Russian; does include English). They explain that it requires a one time activation using VPN (simulating Russian origin?). There's a tutorial guide to do it and it doesn't look too bad. I haven't bought this deal as I pre-ordered for $37.50 from Green Man Gaming.
My cousin bought BL2 from this seller ($24.99) about a month and a half ago. As stated in the product description, his game key arrived as a photo/scan in e-mail and it worked and continues to work fine on Steam (we've been playing together; Atlanta GA area). His CD key was region-free so he didn't have to go through the VPN activation.