OK so if you're saying I will probably be using 7.2 KWh/day and the energy data for the UK according to the wiki link is € 0.0436 how much would power consumption be a day?
If that is the correct price per KWh (and I have no idea whether it is), then its 7.2 times 0.0436 = € 0.31392 per day. This is approximate because the 300W power usage was a rough estimate.
OK so you're stating it could be close to £0.40 (GBP) a day of power usage, it doesn't seem so bad.