Out of country for closing. Power of Attorney to Realtor?

[Petra M.]

I'm going to be out of the country at time of closing. 

Seller is adamant about the closing date and I'll lose the deal (and earnest money)  if I move it. 

Is there a way I can sign the closing documents? I've heard of people doing it at a U.S. Consulate, but they charge $50/signature. The alternative is granting the buying agent limited power of attorney.

Anyone been through this?