I bought my 2000 Boxster in December 2011, and since then have spent more than I think my wife knows. The latest addition was a set of 18" wheels that I had refinished and put on new rubber. I put on a NHP muffler and some exterior bits - smoked side markers, a silver/black emblem, and replaced the broken Boxster script.
I wrapped some of the interior pieces with carbon fiber wrap, but I'm thinking of having them hydro graphic'd for a more professional look.
With maintenance costs and the add-ons, I think I'm easily close to $3000.00 (I had to fix a dent from the previous owner).
I don't mind spending the money cause it makes me smile every time I hear that engine roar.