For that price, it is probably better to shoot for a DT FS. It seems Yan has taken out IXNS from ebay but FS is lining up now. Suspension is highly recommended if your commute route isn't smooth. I got a DT IXNS and just realized that a part of my commute route is quite bumpy. Wish I got a FS. For 4-5km, I don't think you will carry the bike a lot, e.g. up and down on bus or train. So, I would say a suspension bike is much better.

As of YEAH, I asked the seller, too. It doesn't have telescopic handlepost like 2007 Dahon does. Besides, the pictures on the page aren't consistent. IMHO, that tells the quality of the seller.