A recent completed listing on eBay had
Aragorn, King in Exile at $6.50. The one with the Buy It Now option for $9.98 did not sell.
With that in mind, I would probably put the
King in Exile around $4-6.
Aragorn's Bow (foil) is a nice card. For a while, that was the most sought after card in the game (well, during Fellowship Block, at least). I would think you could probably get $15-20 from someone who really wanted it. If I needed it for a deck, my opening offer would be $12 (which I think is reasonable).
-wtk