The house is sold for more than £50,000, so the second price is used.
For the first £50,000, the agent charges 3% and 3% of £50,000 is £1,500.
There is still £89,000 - £50,000 = £39,000 left to deal with.
The agent charges 2% on this and 2% of £39,000 is £780.
Therefore, the agent charges £1,500 + £780 = £2,280 in total.