I don't think he's the only option, but he's certainly the best.
I kind of look at prospects the same way I'm looking at Buffalo's draft picks right now. Ultimately you have to turn those picks into players worthy of being on a Cup contender. Stockpiling 2nd/3rd tier prospects is only good for the farm club and to eventually package them for top prospects or roster players that are worthy of being on a Cup contender.
So trading for a Prince or Zucker might be part of the process, but I don't see it as a step up in that process. It's more like shuffling cards in the deck to me.
I know teams won't likely trade a Coyle or Toffoli, so that forces a GM to go back to packaging lesser picks/prospects in an overpayment for that player/prospect, or for that top-5 draft pick. One way or the other, eventually Murray will have to make a move like that. So if those "A" prospects can't be had today, then I'll hope Murray acquires more picks for a bigger trade on draft day (this summer or next).
I want to see less Carrier's and more top guys or top picks (at some point).