https://www.massdrop.com/buy/ergodox/Options:
Switch types -- Black (+$0), Blue (+$0), Clear (+$0), Red (+$0), or None (-$44)
Case style -- Classic (smaller) or Full Hand
Keycaps -- None or Blank PBT DSA (+$37)
Case Material -- Clear Acrylic (+$0), Aluminum Top Plate (+$25), or Gold Plated Aluminum (+$5,000)
Assembly Service -- None, Partial (everything except the switches) Assembly (+$20), Full Assembly (+$50)
So the cheapest using standard options would be $155 (no switches), and the most using non-gold standard options would be $311 (keycaps, aluminum top plate, fully assembled).
Edit: Seems like there was a hiccup with the start of Round 4. As per what is posted, it should restart again on Thursday, 2013-08-14 @ 16:00 EST.
Edit2: Now live! Go and bring sweet relief to your haggard fingers.
Edit3: Lowest price unlocked. Go buy!