I have the west covered by NG Topo! and also love it.
They have discontinued Topo! including the state series though which is weird.
I don't know of a better option out there that offers the same abilities, so why not continue selling an existing product? Either way it still works and now the used state series are selling for more.
In some cases more than the former new retail price, if your lucky enough to find the states your looking for. I would like to find Hawaii, mid west, and east coast states to complete my Topo! if anyone has them or knows of something.
Eric