I have always found that this time of year is the best time to put up your prices.
Its going to be busy for the next couple of months, so a few customers that moan about your new prices dont really matter !
It also allows you to offer discounts in Jan and Feb, without really discounting your CURRENT price .
Stick £5 to £10 on now,,,,,,,,,,offer £5 to £10 off in Jan and Feb.
Its worked for me anyway
regards
Chris