I have 36,000 miles and so does my husband. He is unlikely to use them before they expire but I may book a flight to Australia. I've looked at Emirates FAQs and it tells me that it costs 25 USD per 1000 miles if I transferred my husbands to my account. So, about $900. I would then have 72000 miles. What would I get towards a business flight? Would it be worth paying $900?