Tesco Alcohol boob in Scotland leads to give away prices..?

I went into Tesco looking for energy saving long life light bulbs,I am green,I saw ones for �5.00 and thought that was a bit steep so I took one over to a staff member and asked them to check the price and it was �1.00 so I got three.The next day I thought I should have bought a few more so I beat a trail to Tesco only to find the shelves had been totally restocked so I asked the same staff member where the �1.00 bulbs,she laughed and said I should not have brought it to their notice that the bar codes were wrong so I was lucky to get my bulbs saving �12.00,a small victory.