Moderators generally don't "police" anything. Maybe if they see a thread that's obviously going to be a hot-button issue... I don't really know how often that even happens.
As you mentioned, it's usually up to members/users to
report violations by clicking on the little triangle of an offensive post. Then mods will take a look at it and decide if it requires a warning or whatever.
How on earth would they have time to go through every closed sales thread and see if someone deleted a price? Or deal with some disgruntled character going through and reporting them all? That's crazy. Most mods have jobs, families, hobbies outside of BFC, y'know...
lives. And they're not paid to babysit us.
FWIW I generally don't delete my prices in old sales threads. In fact, I don't think I ever have (but I
almost never say "never" because if I do, surely I'll have to eat my words

)...
... but I'm not terribly concerned about other professional makers, dealers, or just "regular folks moving a few knives a year" deleting theirs. With the vast resources available outside this forum for comparison purposes, I fail to see why it's such a big deal. I think the mods do a pretty darn good job of letting the Exchange more or less run itself.
Bingo... and here's a good example of letting the market decide:
:thumbup:
There's also the unfortunate fact that steel, belts, electricity, etc never seem to get any cheaper year after year. Even disregarding increased quality and demand... If someone asks to me to make 'em a knife for the same price it sold for 1 or 2 or 5 years ago, I will happily advise them to try the same tactic at the gas station or grocery store, and let me know how
that works out for 'em