Where are you hoping to go on a business class ticket? You may have enough MR points already. While most airlines charge around the same amount of miles for award tickets, there are some programs that are a much better value depending where you're traveling from/to. For instance, most airlines charge around 100,000 miles for a business class round trip award ticket from the US to Europe. However, ANA (a Star Alliance partner airline) has a distance-based award system. For roundtrip business class itineraries on any Star Alliance partner airline up to 7,000 miles, the cost of a business class rountrip ticket is only 63,000 miles. Up to 9,000 miles the cost is only 68,000 miles. So if you live on the east coast and want to travel in business class to London for example, this is a much better value for your points. You could get a roundtrip business class ticket from NYC or Boston to London for 63K miles or from Miami or Orlando for 68K. And I believe if you transfer your points to foreign carriers AMEX doesn't charge you an excise tax fee like they do for US carriers.