Thanks guys for your answers, very helpful.
It looks like payment is not really done by the hour, more the session say lasting 1-4 hours.
From what you've all said it looks like rates go something like this;
$50-$150 per session for softcore
$100-$300 hardcore
Or thereabouts.
The reason why I'm asking is that I'm looking to get hold of a lot of niche content which is very hard to find, so I figured I might as well commission my own.
Oh and one final thing when are all you Americans going to learn how to properly pronounce the word niche?
It's neeshe not nitch!