I never really considered this, as it's a section that has been that way since I registered here. I might swing through there and experiment a little myself now that you've got me thinking about it.
I would say report the thread and see how it get's handled. Definitely give a good explanation of why, but your reasoning is on point. - How can someone bid in a locked auction.
I also think reporting any auction that doesn't have auction terms would be a good idea as well - End time, Starting Bid, Bid increment
It would be nice in the Marketplace if you couldn't toggle the "lock topic" option. This way once it's locked it fades into obscurity. I'm also not a fan of self-moderated topics in the Marketplace, sure some users have shown they can use this responsibly. Unfortunately it's generally a lazy attempt at a scam. I remember once discussing being able to pin your thread to another one, it's not a great idea but I though it would be an interesting way to counteract suspicious locked/self-moderated sales threads.
You have a logical point of view, but will this solution change anything? I do not think so. Some can bypass it by moving topics to that section or devising new ways of scam.
The solution that has been applied is an acceptable solution as there is a warning about *Possible scammer* shown to guests.
~snip~
Just because they will try to find another way doesn't mean we should give up on making it more difficult for scammers. If the Marketplace becomes a more transparent platform for sales they will want to move the scam threads elsewhere. That would take them off-topic for those boards and eligible to be dealt with by moderators.
~snip~
Locking a thread should be the counterpart to a bump.
Therefore, locking a thread shall let it plummet to the last page of the board.
~snip~
If applied only to the marketplace that would be an interesting idea. They would gain zero visibility by locking the topic on creation.
