Ach, that's a hard question.
Conservatively I would say $20k for a kitchen and $10k bathroom. It depends on lots of things of course - if it's an older place you ahve to be careful with Bathrooms, you never know what you might uncover underneath.

I'm about to do my bathroom for $1500 and my dads for $6k, but that's because I'm doing lots of it on my own including sourcing all the fittings, pulling the old ones down (woo HOO!) and I'm not getting a company to design it.