How do you decide how much to spend on an RV

Your money your choice, the first 2 of the RVs we purchased of the 4 we have had over 3 decades of RVing were new, the drop in value was significant not to mention the hassle of dealing with getting the bugs worked out under warranty. Last couple of RVs including our current class A were well cared for, lightly and gently used rigs that felt like new without taking such a drastic depreciation hit. We are also near retirement age and feel going used made for a remorse free buying experience, several years later our rig can still be sold for what we have invested in it although we have no intention of selling. Have fun shopping, hope you get the RV you want at a price you can live with.