I have a 2009 Dahon Cadenza Solo which I converted to a fixed gear. It ticked all my boxes: 1) affordable, 2) folding, 3) big wheels, 4) looks nice, 5) decent components.

I recently built up a new fixed gear and plan to use the Dahon for a single-speed tourer now, since it comes with every mounting hole you could possibly want! All in all, loved it as a fixed.