I value my miles at whatever I could buy them for - for example 2.5 cents for AS miles - because I have no difficulty redeeming them for much more "face value".

My reasonaing is that on TATL/TPAC F/C/J awards and MFUs the apparent value is much higher. For example BA 25k LAX-LHR MFU works out ~15 cents/mile. Additionally, I have paid >$2500 for a TATL C/J ticket (out of my own pocket) in the past, so this valuation passes that test also.