As for the guy paying 2000 yuan for all night, that's way overpriced. But I know of some hot russian girls here in SZ they go for 1000 short time, I'd never pay that but plenty of guys do. No idea how much they are for over-night.
I was in Dongguan city in 2007, went to a 5 star hotel that caters only to mongering (many there) we were there for opening night. We ended up getting KTV room, you pay for the girl to sit with you and play dice games, if you don't like her you kick her out and get a new one. During this time you kiss and fondle etc. At the end of the night you decide whether or not to barfine her for 1000 yuan for over-night plus hotel room. Yeah it's not cheap but once in a while it's a fun experience. All these girls were 9s and 10s. They have the girls line up in front of you in the KTV room, about 30 at a time, we were picky and had another group of 30 come in the room. You definitely feel like a king.