I'm heading to San Sebastian, Barcelona, and Madrid with my two teenagers next week. The good news is we'll be in Spain for two weeks. The bad news is that unfortunately, we have a very tight budget. But we would like to eat well nonetheless. We're all pretty adventurous eaters. Our only limitation is our wallet. I'm trying to steer clear of the Fodors etc. picks and would love your suggestions for great spots in any or all of these cities. Thank you!