Dolan Pre Cursa / PreCursa / Track Champion

Different frame; better tubing, different ends, maybe tapered fork/HT.
Big variation in sizes on (DB3) & more paint finishes, prob ordered in much smaller batches or as one-offs hence the price leap, or maybe fabricated or finished more locally than Far East.

Each frame above appears slightly different:

• Blue and black look like they could have a tapered HT while orange appears straight 1-1/8th.
  
• Orange fork legs also appear to differ, unless it's just bad photoshop.
  
• Blue & orange share the same track ends & stays.
  
• Black one appears to have a fatter top tube, different track ends & stays...
  
  

... But these again seem to change depending on what frame colour is selected (!?).
DB 1 (in brushed alu or bronze pics) looks like it could be a Histo type faux-pro with a reasonably short HT, which is good for fixed TT/track pursuit types (thumbs up!).

lol, credit where credit's due, maybe they're ripping my idea of having three nearly identical frames of the same type, but building each up differently :-D