Originally Posted by corporate-wage-slave

It's open to debate this.

Using UK sterling: You can buy Avios via obscure channels for about 1 penny each. You an buy them direct from BA.com for 1.6p each, sometimes less in sales.

The worst value redemptions you can make, which is typically for part pay with Avios (reducing a cash ticket cost by using Avios) is around 0.6p per Avios. Similar for car hire/wine/hotels. For mainstream redemptions, including something like Reward Flight Saver tickets to ATH, you can usually do a lot better, 2p per Avios isn't unusual particular if it's a single ticket. It goes up to around 4p per Avios with things like ski destinations during school holidays or one way Upgrade using Avios WTP to CW on some longhaul sectors.

So I tend to say Avios can be obtained for about 1 penny each, and therefore you are making good use of them if you can get two pennies worth of value from them.