Does anyone know if the airbnb posted rates include taxes? Thank you

What taxes? Where? You are dealing with individuals advertising their accommodation on this directory, look to their advert.

If your question is whether there will be added tax on the price quoted, the answer is no. These are individual people who rent out rooms in their apartments all over the world.
the only tax/fee is the airbnb fee and I believe if I remember correctly that it is taken out of the total.. I think the host gets 97 or 98% and airbnb takes 2 or 3% as a fee.... You can go to the website and read about who gets what and when.