I've just checked Ebay - the vast majority are already unlocked. Like I say.. if its out of an ericsson box, it'll most likely be unlocked.

If going down the ebay route, read the descriptions carefully... if it doesn't say its unlocked, then its probably not. If in doubt, ask them!

Edit: Friend of mine has one and has no problems with RF. It depends on the firmware revision. Early ones will be buggy.