Not really. Once they quote a final price, they would lose Face if they then agreed to reduce it. And no Thai will ever do that.

I bought a shirt at a Chiangmai street market. Bartered the seller down from 120 baht to 100 baht. He then agreed 90 baht if I bought 3.

They were of reasonable quality and good value at that price. I paid him 270 baht.

He restocked his stall with more stock and I picked a further 3 shirts. He wanted 120 baht each!!! Then 100 baht each. It took some time for him to agree to sell at 270 baht for the three new shirts.

When he had realised that I wanted more shirts, he must have thought to himself that he had agreed to too low a price for the first three shirts