I am wanting a little persuasion

We don't do a lot of camping although we are always hoping to do more in the future. In fact this year we got away for 1 weekend. Regardless of how much camping we do we need an RV to do it with and our current unit is starting to show its age. I need some help justifying spending some money on upgrading to a newer unit. How do you determine how much to spend on your RV? Should it be $1000/night of annual use? Or maybe a percentage of the value of your house? Any thoughts?