I tend to use mine to UUA from WT+ to CW.
the fare difference would be from £700ish for WT+ to £2000+ for CW.
SO i guess that would equal a rough value of £0.065 (US$0.10) per avios. However I could never actually justify spending £2000 on a flight. so I suppose it doesn't mean that much!
If you have the opportunity to use them in the future to UUA from WT+ to CW and can afford the $112, then I would save them, but thats just my 2pence worth.
In the end we got them for free, so anything they give us back is a bonus!