If you work from home on a self-employed basis then there are some home expenses you can claim which are dependent on whether you use a room solely for business purposes or not.
Take a look at the guidance here
. If you click on "Next Page" at the bottom you will find some examples based on different circumstances.
Fees will vary from accountant to accountant depending on the size of the practice, where it is, the profile of the clients, the type of client the firm is trying to attract and any number of other variables.and should be agreed in advance, preferably. I cannot tell whether the fees you have been charged are excessive as I don't know how much adjustment was made to your Sage records by the accountant, how much other analysis they did or whether the fee included your tax return.
I know accountants and tax advisers who have trained clients to use Sage and who do very little tidying up because the client wants to keep the fees down but that's not how I operate. It's always possible to find someone cheaper but as with anything else, you get what you pay for.
What worries me is that your accountant missed out legitimate expense claims and if I were you, I'd consider finding another accountant, preferably one with more tax knowledge.
I hope this helps but let me know if you have any further questions.