Haven't used BA in years and notice my few (about 9300) Avios points will expire end of this month. After reading FT about using Avios, I now see I can use these for future short-haul US flights. Since I'm not ready to book anything yet, what is the cheapest way to save these miles? (On another airline I once saved miles buying a single $1 iTune from the affilated online store or a slice of pizza from their dining site, but see iTunes via BA eStore requires a gift card purchase or the like.)

Any other inexpensive ways to keep these miles? Funds are very tight due to family illness.