I have 90000 skymiles and my wife has 70000. I also have about 16900 SPG points that I can transfer to her delta account. Two business class tickets to europe is 90000 skymiles each. One option is to buy 3100 SPG points and transfer to her delta account. It costs 175 bucks - is there another way to make those 3100 points? The other option is to buy two round trip fares and upgrade to business class. What would you do?

Thanks.