This fare had some interesting dates in the November as well - but when I finally decided to book 4 days in Miami on AF (34 500czk/1320euro) on the last weekend in November, it was already gone.. This was so far the best deal I have seen ex PRG to Miami in my whole travel life
My bad I didnt post this enough in advance for the others (been 100% sucked by the evil corporation in past week)..
Worth to mention there was also LAS available for great price, with much wider availability.