If you have the miles, it's worth it. Spring Break is a very competitive time for award seats and your avoided cost is just going to keep going up. I tell people who are planning to purchase tickets to warm places for Spring Break that they really ought to have their trips figured out in the early fall and be booked well before Thanksgiving. You're lucky yours is so early. Sure, it's a drag not to get miles for a flight -- but that is ultimately what happens with award seats and you can pick up EQMs for a whole lot less than what this trip is likely to run if you purchased your ticket. (As for the numbers, wouldn't Acapulco be a minimum of 35K regardless? Laying out 47.5K doesn't sound too bad, all things considered.) In your situation and knowing the dates you need, I would say: "Pull the trigger now and don't look back!"