there is a website called
www.gatwickcrewaccommodation.com they are a bit of a rip off, but good as a last resort if you can't find anything else. All the houses are with older single ladies. Perfect for quiet nights studying. A girl I flew with on a recent flight, commutes from Glasgow, and she said she stays at a hotel in LGW, which is only £15 per night. I think she said Travelodge, but I'm not sure. You might need to call them and ask them for an industry rate, ie tell them you work for Virgin.