I've just paid my annual wealth (patrimonio) & renta tax 328.41e, it's only a small property so depending on the size of your friends property the amount your friend paid may be correct.
I also pay around 80e a year for the solicitor to act as my gestor. If the home is owned jointly then you will have to pay double as each person has to submit a form.
Question to ask is how long has your friend owned the property, this could be the first time they have paid tax and a couple of years could have been paid at the same time, so the amount might not reflect an exact years payment.
You don't have to have a fiscal rep unless your tax affairs are complicated. If it's purely a holiday home which is not rented out then you can complete your own form (214) lot's of people on here do.
We're all waiting to hear whether Wealth Tax for non-residents will be abolished, latest reports say that it's up to each region to decided if they will follow the ruling.
This tax brings in a lot of extra revenue and the concensus is that we will still have to pay it.
As non residents if Wealth Tax (patrimonia) is abolished we will still have to pay Renta (this tax was brought in as a lot of people where renting out and not declaring the income so now we all have to suffer. This tax is minute compared with W/T so most people myself included will make the effort and fill out the forms themselves.
This is going to have a big impact on the solicitors/fiscal reps annual incomes. Most fees are paid in January for the W/T to be paid in May/June so we all have until December to decide whether to cancel our agreement with them.