private area for registered users

can you suggest a way ( plugin)
to provide for individuals who are registered
to have their own private area of the wp site?
example:
client wants to have visitors pay for advice.
they pay a certain amount, and ask their question.
he answers the question on their own page, where they can go to see it.
they alone can go to this page,is private to them after they login they are directed to it.
They might have this page created automatically with their registration.
it seems to me there might be a plugin for this sort of thing.
any suggestions?
ed