I am buying and trading both models with and without the original box. Usually with a box you pay more, depending how rare (or not) the model is. I also buy models without box, as long stored in a display cabinet and not scratched or bashed by kids hands.
In this series of posts I will discuss the most common problem you face as collector.
I bought 7 models for 12 Euro. Opening the shipping box was already a nightmare, the previous owner must have been a 24/7 smoker by profession. The interior and the body covered by dust and some yellowish stuff (that usually sits in your smoker lungs I guess). The good thing, these models can be disassembled easily and cleaned up, though you can try to use an airbrush blower to clean it without taking it apart. The yellow residues can be removed with car polish.