I've done the same thing you're into a time or two.
Several years ago I bought a late 70s or early 80s Japanese road bike. Takara brand, made of high-ten steel. I immediately scrapped most of the components and converted it to a fixed gear. I specifically chose this one because it has semi-horizontal dropouts, the frame was in decent condition, and it was offered for a mere $25.
After riding it with FG for a while, I decided I wanted a single speed, so I reconfigured it again. Then I decided I wanted a 3-speeed IGH, so I changed it once more. I've left it alone for the past few years and just might end up keeping it forever.
The wheels on it now--both built by me--look good and work really well. The wheel components were not terribly expensive, although I did spend more on them than the entire bike would sell for now. That's okay, since I didn't build it to flip, but to ride. It weighs as much as a tank, and that's okay too, because I have other bikes for when I want to go fast. This one is is like Forrest Gump: kind of slow, but very nice.