They do not allow trading or for sale posts on this site. The reasoning we got in the beginning was that they receive advertisement revenue from people who pay to have their buy, sell or trade lists included in the actual magazine.
This policy is posted in the very first post in the Announcements from Fine Scale Modeler forum under the title FSM Forum Guidelines.
There are several modeling sites that have established trading/sale forums:
www.missing-lynx.com flea market
www.hyperscale.com plane trading
www.armorama.com buy/sell/trade