Can be anything depending on the model pussyserver.
Some may not exactly be what you would call a "model" - just local talent and worth very little. A girl with a rep or some following can be *anything*.
Depends again on the country.. US is cheaper cos of dollar value, but eg EU is generally a little more. An EU "agency girl" could be averaging $1400, but ya can book her private at maybe $600. But hell.. some are only $200 etc.
Can't remember the exact figures, but one girl was...think either $12K or $14K, but that was only because she was booked up for 14 months and had several contracts running, done movies (Bond girl blah) and did a theater show each evening. (These type of models can't afford to do hardcore porn - but, well, sometimes do

)