Hi daveyboy!

There are very very few hostels near the airport and I'm almost certain that NONE of them are cheap. Everything around the airport caters to the business travelers and so they can charge what they want. The ONLY hostel with a website near the airport is Hostal Los 5 Pinos @ http://www.Los5Pinos.com . It's not cheap (at about 54 Euros for a single) but at least it's cheaper than a hotel. Good luck!

Saludos, MadridMan