Another expense would be how much of the tourist thing you want to do. Some places are very reasonable and some you can spend a ton of money before you realize it. What the wife and I do when we visit someplace new is to sit down either online or go thru brochures. Every state has welcome centers and they love loading you down with sites and attractions. Plan the ones you really want to see. A lot of historic places you can learn just about as much from the outside as you do from the inside. Some are not worth the price of admission. Many run by the NPS are free, some are not and some take donations. If you are traveling with children, you may plan to see more than if it is just the two of you. Another huge expense is dinning out. Decide ahead of time how many meals out you want to eat. Something to do for fun is to create a blog of your travels. This keeps family and friends back home up to date with you plus it is just fun to do.