I wouldl ive in San An, if you want night were you can go out and not pay so much for it - West end is however filled with beerdrinking footballers (not in the spirit of the genuine clubbers!), but there are a few good places there Play2 and a couple of other places where you can get in for free + recieve a free beverage (shot or similar).
Ibiza is pricey, but check out the spotlight site for more info´s - there are hostals in San An. for instance Hostal Norte or in the town - Hostal Marina, they arent that pricey but don´t expect comfortable beds or anything...Marina was better than Norte! Lived in both, since I wanted to save money for the clubs and so on.
You schould concider going in July/August. If you can, get a package deal with hotel and return tickets! It´s fordable concidering the alternatives (planning your own holiday) - If you want to plan on your own, try and check out the Apanish airline company Iberia
www.iberia.com -
Hope this was useful! But: save your money now, Ibiza is EXPENSIVE! (If you want to experience the genuine side to it!)