Yes, you can do Spain on €25-35/day...if you don't go anywhere or do anything. While I budgeted for travel from city to city, I didn't budget for inner city bus fare for times when it was absolutely necessary, attraction admission fees and other incidentals.
Here's where I went over budget...
- Museums & other admission fees
- Inner city bus fare, i.e. Mirador in Granada
- Lost sunglasses (replacement) - €9
- Extra lodging - extra night in Nerja (WORTH IT!) & 1 night stuck in Aranjuez
- Phone cards - €17
- Internet cafes
- Lost money - €20 (that hurt!)
- Increased fare to Barcelona because of last minute ticket purchase
Luckily I'd budgeted to go overbudget by about $200 (US), so I was okay. I will use this experience to budget wisely for next year's excursion.