If you plan to check bags, you probably don't want to re-fare a WGA to Basic...
If you're not sure if you will check bags, then you have to really think about it. I avoided doing a re-fare to save about 1,500 points on one leg of a flight (flight home) because I may buy liquids and may need to check the bag coming from that destination. But for the flight going there, I re-fared without hesitation as I try not to check bags on the way out on a trip anyway.