Radio 4 recently gave the average insurance premium for a new 17-year-old driver as £4000 p.a., so £1000+ for a 24-year-old does sound quite reasonable.
However you might find that you can get a significant discount by adding an older, more experienced driver (such as a parent) onto your policy as a 'named driver'. There have been several posts here on AB from people who've found that they've got much lower quotes by doing that. (Unlike 'fronting', where you get a parent to insure your car in their name with you as a 'named driver', my suggestion is completely legal).
Chris
PS: While insurance premiums can sound ridiculously expensive, you need to remember that a driving error by you might leave another person requiring life-long medical care, forcing your insurer to pay out several million pounds. Insurers take on a big risk, so it's hardly surprising that they charge high premiums to novice drivers (particularly when you consider that the vast majority of drivers have at least one accident in their first two years of driving).