Originally Posted by CalifTraveller
I travel (frequently) that is compact but still a reasonable fast ride. I ride a road bike (Raleigh R700) and commute everyday (Giant FCR) and enjoy bikes with a longer reach (27-29") and high pressure tires. Because I'd take the bike on buses, trains, and in suitcase for flying, I'd like a pretty small fold (lighter is also a bonus) and a bike I could put in the suitcase without too much hassle.
How many times are you intending to boad the bus? If you intend to board the bus very little, go with a 20' inch folder. Buy a hard case for travel and that's all.
You crossed off Brompton, Bike Friday and the Birdy because of cost. That leaves you with Dahon or Downtube for folding bikes. You really need to look at Dahon because they probably have a bike within your price range plus you get dealer support.