Question of Value

Fellas I have a question in regards the value of a given set. For example, recently i was on a quest to get my hands on an authentic Porsche GT3 42056. After getting duped twice was able to get my hands on a pristine set. I feel the value of this particular set will increase over time. Decided to search for another. I bought a 2nd and this particular set is in an original Lego shipping box. Its on the way to me and should have it this week. Question is, if both sets are brand new but 1 is in...