- Because it's rude, and it creates needless friction in the threads.
- Because items are worth what someone is willing to pay for them, not what 'the cheapest possible price anywhere' happens to be. Often, a person is quite happy to pay more if they know the history of an item or can get it quickly.
- Because the seller may be simply recouping funds when they sell something they themselves paid a higher price for. There's nothing wrong with that, especially if the buyer is happy with the price.
The marketplace here isn't about delivering the best deals to buyers. It's about having a place to exchange goods between members at prices that are agreeable to both parties.
If you're concerned about the price of an item, then research it for yourself. And a polite PM to the seller may be appropriate. But the price policing rule definitely serves a purpose, and we're going to keep it.
“I think that when the lies are all told and forgot the truth will be there yet. It dont move about from place to place and it dont change from time to time. You cant corrupt it any more than you can salt salt.” - Cormac McCarthy