I just finished upgrading my Vans RV-7a to ADS-B IN/OUT, and I came out $2,500 ahead

I just finished upgrading my RV-7a panel to ADS-B In & Out, and I came out over $2,500 Ahead by doing it. I wrote up a description of what I did.

http://www.thehdpilot.com/blog-article.aspx?id=53

I have an xm portable in the car for music. I bought a second installation kit (mount, antenna) and wired it into the plane. When I fly, I just pull it from the car and slide it into the airplane mount. Using the OPs logic, since I already pay for the music in the car, this is 'free'.

So I dropped xm wx for my $500 Skyradar, displays for free on my GRT HX; I pay nothing for charts since WingX is free to me, and am thinking of a Trig transponder (lot less than a 330ES) for ADSB-out. How much am I "ahead"?

BTW, the 330 (and Trig) are the same height and width as the 327 but do need more room in depth.