I understand flipping will happen - and I get it. Someone will always show up after a drop - that's life. To restrict it would be ridiculous and detrimental.
....on a slightly different note, here are a couple newb/non-paying members doing some extensive, daily "poaching" on the Traditionals FS sub-forum. I have talked to some other members and they have noticed the same ones as I have. I have messaged a moderator on the forum and no response.
One in particular (I cannot figure out how else) must sit in front of his computer every waking hour of every day hitting the refresh button every minute or so. As a result he has picked up the lion's share of the best deals since he joined (as a non-paying member) in July. His accumulation often shows up as the first post in a FS thread as trade offers - since he can't sell. This non-paying member is doing a significant volume of transactions & is essentially running (at the very least) a part time business on the forum without permission or being held accountable.
Bottom line, I am loath to offer up anything/solution as I am sure there are more good people among non-paying members than bad. I've been a member for 17 years and keep my paying membership up when I am active. For me, the forum offerings have always more then covered the membership cost. I've been retired for a few years now. I am also a former knife maker and am still a collector. Money is tighter and I cannot be reduced to paying whatever the BIN price is on Ebay. BF has been a community and a refuge.
I would hope some moderators are listening. PM me if you would like more info.