I guess officially it's against the rules but I wonder if they'd consider rethinking this slightly. Sometimes it's easier to find things in the related thread than trawling through the clearance bin!
Often I have found that casual mention of regret of missing out on something while not actually asking for it will sometimes get a PM with a message of " I have such and such for sale"
That being said, I think if there were folks posting as to wanting things in the threads, it would get clogged up with requests, etc and would allow folks to get around the requirements of needing a minimum of posts (prevents those who are just lurking for HTF stuff rather than participating in the community).
IDK, just my opinion of course, worth about less than a penny, but I think its a good idea to keep the requests out of the threads. It is hard to find things on the clearance bin though, even with search sometimes.