There are 5 sprints this year @ £100 each, Comp license is £15/year. You may have to bring your car up to spec, harness, gloves etc. Then you have running costs, fuel tyres, repairs etc. You could run a fairly standard car for no more than £1k for the season barring any major mishaps
that is a really good price. obviously there is the hassle of travelling, whereas with track days you can just go to the local ones.
other than that i think that is amazingly reasonable.