After covering the Queen's visit to Magdalen College last week, I filed my copy from the local Subway outlet in St Clement's and found myself with a little time on my hands before Her Majesty's visit to the John Radcliffe Hospital. I popped into the ramshackle Age Concern shop to check on the stock, and although the Summoned By Bells Betjeman first edition had been sold, there were other treasures on display.

On the very top shelf at the back of the store I spotted a copy of Huntingtower by John Buchan. It was out of reach, so a kind member of staff got a step ladder to pull out the adventure story in the familiar light blue Hodder boards.

I approved of the map-covered endpapers and noted the book was a first edition from 1922, but I thought the £15 price tag a bit steep. The staff member politely inquired how much I would be prepared to pay, but I didn't want to start bargaining, so I made my excuses and left for the hospital.

A more detailed investigation courtesy of abebooks online suggested that my decision was the right one, as comparable editions were available to buy at around the £7.50 to £10 mark, although there was not a first edition in sight covered with a dust jacket.

Earlier in the week, I found myself in the bunker at the Oxfam bookshop in St Giles, where my first task was to value a set of the six-edition The Second World War by Winston Churchill.

The Cassell volumes all had their dust jackets and were in good condition but, unfortunately they were a mixed bag of editions, and so I was forced to price them individually.

Before I left, I spotted for sale The Gathering Storm and Their Finest Hour, the first two instalments of Churchill's magnum opus, and was tempted to buy the Houghton Mifflin editions for £5.99 each, particularly as they had once been owned and annotated by the renowned Hitler historian Hugh Trevor-Roper.

The following week, I discovered in Oxfam's Turl Street shop a pristine 1975 Panther paperback of Henri Charriere's Banco, the sequel to the bestselling Papillon. It was reasonably priced at £1.99.

I am now about 40 pages away from finishing John le Carre's Absolute Friends after breaking through chapter eight, which was rather overloading with politics and ideology.

But the future of affable Cold War spy Ted Munby is still in the balance and I can't wait to find out what happens to him.