What £290,000 means for your stamp duty bill
£290,000 puts you into the 5% band, which applies to the slice above £250,000. Your total of £4,500 works out at an effective rate of 1.6% — well below 5%, because the first £250,000 is taxed at 0% and 2% respectively.
First-time buyer relief is worth the most in this bracket. If you qualify, you would pay £0 instead of £4,500, a saving of £4,500. That relief vanishes completely above £500,000, so it is worth checking your eligibility carefully before you agree a price near that ceiling.
For context, £290,000 is close to the UK average house price. Your marginal rate at this price is 5%, meaning that is the rate charged on the next pound you add to the purchase price.