Hi Luca:
In my opinion, you are dealing with a challenging issue that seems to be swept under the carpet by most Christians.
You may not like my opinion, but I do believe if we claim to be real disciples, we do indeed need to give up all sorts of things - videogames, diamond rings, fancy houses, pool tables, etc. Despite my desire to believe otherwise, I think that the true follower of Christ will give up everything but the essentials. There are some exceptions to this (e.g. no one needs to spend $ 100,000 to go to medical school and become a brain surgeon, but obviously God wants some Christians to be brain surgeons, etc.).
You don't even need to be a Christian to see the moral imperative here. How can anyone, in good conscience, take a $ 10,000 vacation when millions are perishing in the world for lack of the basics.
In short, my opinion is that your "pangs of conscience" may be the voice of the Spirit.
You will hear the argument that having wealth is Ok as long as you don't place wealth above God. This position is like a building made out of dust - it crumbles on the slightest analysis. The key question I would ask people who hold this view is the following: What does it actually mean to place God above your money, if not to use that money to "feed his sheep"?
Many Christians, including myself to a certain extent, hold onto unnecessary wealth, despite the lives that can literallly be saved by turning that wealth into life-saving measures for the millions of desperate souls in our world.
On the day of reckoning, I am going to feel pretty silly explaining why I kept my DVD player, sports car, and stock portfolio while millions slid away into the darkness......