Prices, reading report after report.
I'm not cheap by any stretch, but in my humble opinion, those of you paying in excess of $100 for a date (in any capacity) might just as well stay home and pay for high priced services where you're at. Thailand is known for much more then bargirls and sex, but honestly, let's be real, we go there #1 reason is for sexual experiences. Paying the same you can find it in Western world is just silly.
When I was in Thailand in 1997, I did a good long stint in Bangkok and Pattaya and had trouble spending more then $50 USD on any date, with most running around $30 USD.
So unless the talent has completely dried up, there is no reason for this pricing increase aside from willing mongers who want to overpay. Overpaying in my opinion gets you less respect and does not equal better service. You see in Thailand, better service happens from good chemistry, making the girls comfortable, making them laugh, being playful, loose and free. That's how you get great service out of the women there.