Apparently they hand pick the sellers seemingly to keep the number down to themselves and their friends.
That's not really the case.
The more sellers, the more competition, the lower prices, the more bitcoins are bought, the more the site makes in commission.
Anyone who does the verification and passes the test (20 basic questions about how the site works that every seller should know) is welcome.
https://bitbargain.co.uk/sellSounds like a huge opportunity exists for a competitor.
Exactly. BB prices reflect supply and demand. If you think it's too high and you could sell lower, just become a seller and sweep the competition. It is pretty much that simple.