if you can't find something used and cheap with 80% of the non-wheelset componentry intact, i'd suggest doing this.

while you can theoretically build up the schwinn for less than 250, you'll be left with a frame that's not something you specifically ordered and it will have road geometry.

you can build it and learn about it, or you can spend a very small amount more and get the windsor(360 shipped) in the color and size you want.

i found a bike already converted and ready to go for best offer... 75 bucks later i had a fixed gear- if you don't think you'll get that lucky i would suggest you think about what you want.

if you want a bike that's old and problematic, be cheap about it. if you want a bike that's old and has good components, you'll probably spend about as much as you would on the brand new windsor.

in the end it's your decision, don't let anyone else make it for you.