Frank, I paid something silly like 39p for one from Home Bargains a few weeks ago.
When we moved here some of the fittings had bulbs in them that cost around £20 each and could only be bought online. Some flippin' government directive had been put in place dictating that new builds had to have a percentage of these fittings to ensure that energy saving bulbs were used and these special light fittings would only take 3-pronged bulbs.
Of course, the easy way around this was to take out the actual light fitting and replace it with a normal one
Only one bulb has blown so far but as each one goes the fitting will be replaced.