Was that mentioned in your PM response or that you just wanted to keep, slab, and sell later? I actually had a sales thread sometime ago that I mistyped the price and someone took it. I was my bad so I followed through, I left the 1 off a listing so a difference of $100 from FMV. I have also posted the take it when I saw it was an error to protect the seller and I had no intention of buying.
There was a thread a while back about this very subject as to whether the seller should honor their prices even if a mistake. I wonder if you can post in the sales thread opening, if you post something in error such as price, you reserve the right to refrain from selling until after you add the correct price but that would really muddy things and give the seller the perfect remorseful out. I guess the safest would be to create in the testing thread and review thoroughly before listing in the sales thread.