I'll be there again this year... First year I went (2 years ago) I was working, manning the media entrance over night so I could watch the racing. It was so hot though I managed under 5 hour sleep in my tent over the 3 days! But the rain came on race day, which produced a fantastic race. Last year I just paid up and made the 25 minute drive there each day. This year will be the same, can't wait!
One tip I would give is to take your own food if you're not wanting to spend too much. The prices are pretty crazy! Also, if you have tickets for a particular stand then don't sit in the same stand for the practice and qualifying days, move around and see other parts of the track. Get over to famous corners, like Club and Vale, or Maggotts which is the fastest corner and maybe even the pit straight to see what's going on in the garages.