I love my Janome 6600. It is a great machine. Like someone else said it doesn't have that free arm to be able to sew on sleeves and pant legs easily. That is the only thing that I can say negative about it.
I don't know what a good price would be. Like others have said with the new model coming out in a few weeks you might be able to pick up a trade in at a good deal ( I would never trade mine in though
)