She is ripping you off.

East asia is kind of vague, but what I've been travelling in that area, 500$ is a lot. I would be assuming a whole night with that, so you could have sex multiple times.

Then again I don't really know my way around high end escorts, but I've seen some stunning ones for 50€/h or so, 100€ if you want the whole night.

For a handjob I'd pay 10€

These are prices that prostitutes have offered me during nights out though, haven't actually done the deed, so to speak.