How much money will I spend by travelling to Puerto del Carmen , Lanzarote?

I plan on going to Puerto del Carmen in July and I was wondering how much money I will have to spend in 4 days. I already found a pretty nice accommodation and first can someone tell ,is it smarter to pay for half board too or should I just eat out in town . And also how's the price of food? What's the average price of a meal out in town? How are the prices if I wanna have a night out in the club or somethin ( like the price for entrance , tails ). And also what other expenses should I be aware of ( except transportation from the Airport to the accommodation). Thank you very much :D