I did exactly that....traded the 55-220mm VR for the 18-70mm, no money involved. All through the wonderful folks here at CS.
Reason why, though one is newer and has wider focal-range, the other is older though widely acknowledged to have great IQ, thus if you see market price, they are pretty even.
It all depends on what you intend to shoot, and the kind of photography you're into.
photography is not about the look of the lens. some lens are built like a tank, heavy but optically inferior, so you can't judge by looking or holding it only. you should know your need by first looking at what you normally shoot.