Motorhome purchase, but what and where

Hello, we would like to buy ( 4 pers.) a camper. If possible, without having to rebuild in the evening so a fixed bed + alcove. Since the children want to sleep in the alcove also no bunk bed. The WoMo should not be older than 8-9 years, have not yet 80000 km and the usual standard equipment Since we then sell one of our two cars, it should be everyday suitable. Now the questions: – Which driving station is to be recommended with which engine? – Are there manufacturers(Au) fbau) which you can not recommend ? – What price do we have to expect ? – Should we buy from the dealer or private ? – What costs arise except the purchase and how high are they ? We would be happy if many camper fans answer, it does not have to be the same to all questions. :-)) MfG Stling