18w energy saving light bulbs are just 47p each in Netto. At 2 hours use a day it will pay for itself in energy savings in just over a month. Or in other words after a month you’ve got a free light bulb. And at that rate the bulb will last 6 years.
If you wouldn’t be seen dead in Netto, Morrison’s equivalents will take 2-3 months to pay for themselves.
I can think of few excuses for not buying energy efficient at those prices.