That is correct.
The For Sale/Trade Forum is for non-profit use only.
If you want to sell for a profit at Head-Fi, you need to become a Member of the Trade ("MOT"). Even MOTs are not allowed to sell in the For Sale Forum. They have to sponsor their own forums, run ads, and do the sorts of things that a business should.
This is an unfortunate screwup on part of a merchant. Someone is going to lose a few thousand dollars because of this mistake. Maybe they won't have enough money to pay an employee, make a car payment or not be able to cover their quarterly taxes with the IRS.
Or maybe this will wipe out the savings they had for their kids' Christmas gifts.
I feel bad for them.
So, please, do not flip these for profit. It's against Head-Fi's rules and we will be keeping an eye on the For Sale Forum.