CDs bought at concert gigs recently:

Richard Durrant - £10 (£10.79 at Amazon, plus postage)
Waterson-Carthy - £10 (£13.98 at mazon, plus postage)
Sultans of Squeeze - £12 (£6.99 at Amazon plus postage)

From this list, it's clear that John Kirkpatrick & Chris Parkinson's "Sultans of Squeeze" CD would have been much cheaper from Amazon. However, the evening had been so good, I didn't actually care on this occasion, and was able to drive home with the tunes from the concert playing away in the car.

A tenner seems to be the going rate for CDs sold at gigs.