Do you think that what ones get from being in Europe amounts to just the net contribution?
Do you even know what those numbers mean? I am among other things a consultant for EU research programmes and I know exactly what those numbers mean but you don't really seem to understand. Those are simply funds that are paid "in cash" versus funds that are returned "in cash", they don't include any indirect benefits - that are orders of magnitude larger.
If by being part of the EU a country boosts their economy by 500 billions a year, those are not counted there. The direct in/outs are irrelevant in comparison to the other numbers we are talking about.
And, please do not make surreal arguments based on how high your salary is... Americans should really learn that one's salary is not a measure of good arguments in civilised countries, and you don't know how much other people make. You may be surprised but a lot of people make more than you - and can still be complete idiots.