I agree that the bucket infant seat (graco, etc) is good for a tiny babe for reasons stated, but I think the way to go is to borrow if you possibly can from a friend or relative because they don't get used for long (if you were in Philly i'd give you mine
). And invest in a Britax for the 'long haul.'
I just decided to get a Britax for dd who is over 20 pounds but who I don't want to have to turn forward-facing for a long time. This one is safe forward facing to 30 lbs. (More info to be found on other threads about this)
Anyway, we just found the Britiax Roundabout at the lowest price I've seen it yet (a 'while supplies last' sale in one particular pattern). It was $179 w/free shipping, at www.babycatalog.com.
Usually they are $220-$250.