This is a great offer if you get the 2-for-1 voucher, but it will help to review the BA award chart before making assumptions about the value of 100k miles alone. There are good values, but also expensive ones you might not expect. For example, US-SYD is 140k in economy. First class US-Europe is 150k-180k. Also look at the distance-based award charts.
Last edited by rrgg; Nov 6, 2009 at 12:37 pm