Not familiar with that exact camper, but seeing that it is a fairly new model year, relatively speaking, it should be a/c ready. That means that it would have the supports in the roof to mount the a/c. I would check with whoever is selling it though.
As for the fair price, check the value here.
RV nada value
But I don't see a redwood listed in 2001. Could you have the year or model wrong? Maybe someone else will come along with more info.