In addition to earning miles through the credit card purchase, you should consider purchasing the ring from a country with a weaker currency than the USD (are there any left?). When my colleagues from Europe visit, they often ask to go to an electronics store, and are amazed by the prices. You could at least fund a trip to Singapore or Sydney if your research shows you could get a 10 - 15% discount by purchasing in a weaker economy. Sure, there are issues to deal with (quality assurance, taxes, returns, etc.), but if you do your research, you could earn 20,000 - 50,000+ miles depending on your elite status. Not a bad start toward the honeymoon.