Yes I keep spreadsheets on all my watch activities....It is not a pretty sight. I keep a separate watch account that my wife knows about but does not ask. I do consulting work on the side--apart from me regular job and that is how I fund this hobby. This keeps the peace effectively. It is still far less than when I was restoring muscle cars/Corvettes. The key is to build/acquire cars or watches you like and will keep, the real $$ damage happens on the quick flips.