As well as getting 18 yrs worth of Career Average, don't forget that the value of each year's contributions will be revalued by an average earnings index so you will also benefit from the effect of compounding and annual pay rises when they come back into play.
It should be noted that the revaluation rate isn't going to be
the 'Average Earnings Index' (which went in 2010 anyway) but 'an' average earnings index (as you correctly state) - specifically, the 'Average Weekly Earnings' (AWE) index. Unison campaigned long and hard against AWE -
government actuaries concede that AWE can fluctuate, in the 3 years to the end of 2010, AWE was 1.7% per year below even CPI. Unison secured a CARE pension revaluation rate of CPI + 1.5% (fixed).
In fairness and in the interests of balance, AWE is assumed by many to be rise 1.5% above RPI (which is assumed to be 4.6% pa) and future CPI is assumed to be 3.6% pa, i.e. 1% lower than RPI (actual CPI September 2010 was 3.1% pa.). But given that public sector bonuses are taken into account when calculating AWE, can I now assume that we'll see a campaign to increase the amount of the average MoD civil servant bonus?!
There is much talk about the RPI/CPI revaluation of pensions in payment. This one though, is going to be the sleeper to keep an eye on.