To be honest, with property prices in Spain dropping and dropping now is not a great time to buy, go move and rent and wait a year or two till things bottom out. Buy now and the chances of you selling it in the near future should your circumstances change are slim and you will more than likely take a loss.
The 'amazing' deal he got you could have been found by you if you went and spent time looking around. There are hundreds of thousands of empty properties in Spain, they can't sell them so prices are still in free fall.