Absolutely the wrong signal.
Two days ago I was walking through the (former) bar district in Hua Hin. It was as dead as I have never seen it before. Restaurants virtually completely empty, no customers, bars closed, locked stores, abandoned dark buildings in detoriation, nowhere a tourist. Same situation on the beach. No tourists!
Instead of increasing the entry fee the government should hand out to every tourist who ventures to come into those lifeless ghost towns a voucher of 300 Baht and give a free meal for the first day. It is the time to think about incentives and not of squeezing brave, venturesome, courageous tourists.