Nobody is able to.
Take a gander at the thread in the News section. Seems like a lot of people have missed it.
Basically, there's no need to ever post in sales threads if you're not the original poster. It artificially bumps up threads, hence, the lockdown. It's saved the mods and admin a massive pile of work and I think it's working well in general. Any questions on products can be directed to the seller.