I think Xúr should have a shop in the tower everyday with one random exotic that would refresh daily as well as an engram. That way you wouldn't always have the coin to buy gear and you would have to really decide if it is worth buying what he has or wait for the next day's offerings. This way you could wait for the item you want most or pick up gear as you go. I don't have a real problem with Xúr but I think this would cause greater variation and more suspense. Just a thought.