Here is the completed trades thread https://www.beeradvocate.com/community/threads/brew-2000.531007/ You can see a few closed deals.
If you're asking whether or not it's a fair trade, the answer is no. Both of the Cantillon Gueuze and 3F OG are shelf beers. They are readily available in Belgium (and Europe) and costs around 6 euros each. You can also buy them online through some Belgian online stores. With shipping cost, if you purchased enough, each will work out to be around $22-25 a 750ml bottle. If you looked at the completed trades link above, it reflects the fact that B2K is a much more limited beer, one-time release, and costs a lot more at retail.
