I would say they are getting greedier. Even in Kata and Karon, they try to get more out the 1000 baththat is the going price.
Yesterday, I took a lady, very friendly out of Patong, not a stunner, but a nice girl next door type. I do what I always do, not discuss any price if they do not. In the morning gave her 1000 bath, and extra 400 to go back to Patong with Tuk tuk. She seemed dissapointed, and argued with the tuk tuk a lot to get the price down, although she got more then the asking price from me.
Anyway, i refuse, except the perfect 10 and friendly to pay more then 1000 bath/night. As said many times before her, never discuss on forhand and give it discretly to them next morning.