Ian,
I'm a student pilot based at Beccles and I can assure you that you'll get a warm and helpful welcome there. A taxi to the festival site will take about 20 minutes and I wouldn't expect it to cost much more than £20 and it will probably be less. Phone numbers of local taxi firms are available at the airfield.
I went to Latitude last year and it was brilliant. It was a really relaxed festival in a lovely setting and the music was superb (Arcade Fire and Jarvis Cocker!). This year I have to miss it as I have to work sometimes so I'll be in India when it takes place
. Just my luck as Franz Ferdinand and Elbow are both appearing!
Just one word of warning...there were a lot of thefts from tents last year.