We discussed having a for sale/trade/wanted section and decided against it.
We have it as rule 4 on the forum rules post.viewtopic.php?f=22&t=543&p=2250
4. No selling/trading of fish on the forum (except by sponsors in their own section of the forum). The administrators of the forum would prefer to not have any business transactions taking place on the board. We cannot control whether or not these transactions would work out well for both parties and as such would prefer to not deal with them here.
Basically we don't do it since we don't want any bad deals to reflect on the forum. People will assume that since it was posted here on the forum, that we are condoning the sale or the seller. If the deal goes bad, people assume that the person (business) involved and the forum are to blame. We also do not want to deal with flames, etc that can come from this sort of problem. I guess the best thing you can do is send pms to people who have them and ask if they're willing to sell them or know a source of them for you.