I'm a huge Villarreal fan and I can genuinely tell you that our finances are almost non existent. We're very much a club punching above our weight with a decent academe. Clever transfers and good team spirit got us into the Liga BBVA.
Selling players is a good idea int he short term but I'd be reluctant to advise you to get used to spending money. Villarreal are a team where you've to build their business model up and generate bigger sponsorship deals before you can really become a force in the transfer market.