I've been living in Thailand for a while now and the market is so unregulated and abused by these sorts of deals.
A big super market near my house runs 2for1 buns every day for the past year.
I've got desensitised to the point where I don't even see the "original price" anymore. The deal price is just the real and only price. The only real deals are the "almost expiring" price reductions super markets put out before throwing out old food.
I wonder if in the grand scale of things this abuse backfires or I'm just a rare case as a foreigner.