I get my coffee from Mancoco - Bags in 250g, 500g or 1kg and they're resealable. We usually opt for either their Espresso or Manchester blends in 1kg bags, and then get a couple of 250g bags of something else. They have new stuff every time so it's an opportunity to try new things from some very small producers, but still have a mainstay.
The blends they always have are typically £28/kg, with the speciality stuff upwards from there
www.mancoco.co.uk