Before I explain I know that this wont suit everyone - This is for a family who are on a tight budget but want a foreign holiday.
I posted a similar deal about this time last year :http://www.hotukdeals.com/deals/holiday-in-spain-salou-8-nights-for/626179
Fly with Ryanair from Luton (other airports are available at the same price just check) 11th May - Girona
Fly home 18th May
Total cost for 2 adults and 2 children = £48 (to get this price you will need to take hand luggage only and use the prepay card to pay)
Accomodation - Eurocamp Internacional de Calonge Staying in a 5 person tent
7 night stay in luxury tent - £119
I know what you are thinking TENT??? but these are great they have bedrooms with proper beds and a living area. OR if tent really is too much then you can have a mobile home for £18 more per person (£72 in total)
£48 + £119 = £167 FOR THE WHOLE FAMILY or £41.75 each
With Ryanair everyone gets 10kg of free cabin baggage which if you use it cleverly will be ample for this holiday which means no extra baggage costs.