If you pay that forum any money whatsoever, you are dumb beyond belief. OK so granted I'm including being greedy as part of being dumb.
It's a clear scam. They will close up shop as soon as they have received the desired amount of funds. Guaranteed.
It's worth it for those who might have enough trust ratings on this forum but for other members who don't have any trust ratings or not enough trust ratings on this forum then it's not a worthy thing.
I've noticed that trust system on that forum is somewhat different from this forum and I hardly see any positive feedback on any member's profile on that forum.
Not sure whether they will run away with the funds or not but according to their admin they enabled the shop so they can support the forum. But I guess most users won't ever purchase anything from the shop.