Yeah ... and twice $100 is $200 (I did that all by myself!) and at that price you get a cool bike, which you made yours by cleaning it up and getting it rideable.
I like to explain it to my wife this way: since I was bitten by the bug, I've ended up with four vintage roadies and a singlespeed built on a vintage roadie frame, three of 'em 531 frames, one all-Campy, one all Dura Ace, for way less than a good set of golf clubs. And bikes don't require green fees.
How's THAT for rationalization?