I want to add my wife's name to a vacation property I acquired. What is the cost and how do I do this

Is there a mortgage? What country?

At the top of the Real Estate Law forum there is a sticky post that explains how to add someone to a deed. You can read it at https://www.askmehelpdesk.com/real-estate-law/how-add-someone-your-deed-91136.html

In Colorado, you can do this by a Quit Claim Deed, It costs $16.00 in order to do so. But if you have a mortgage, you can't add this person to the mortgage as well.