I had thought about this. Some problems that might have solutions:
1. Short selling works for commodities because both sides of the deal agree on the equivalence of entities (a stock, gold brick, whatever). However, what are the specs that make another alpaca equivalent? Some negotiation would be involved.
2. Trust. The seller has to trust me to return an alpaca. To them, someone approaching with such a deal might as well be Bernie Madoff. Ironic given that they themselves have already opted into a bubble of equal proportion.
Anybody have any ideas? The effective value of these animals will approach zero. It's just a matter of when.
Go to a farmer, say, "Let me rent your Alpaca for 100 dollars per year", then sell it on the open market for (whatever) 1000 dollars. Then, wait for the prices to crash, buy them back for 50 dollars. Profit. That's what short selling is. Warning: One Alpaca could just as easily bankrupt you.