Reasonable price for accountant?


Hi just wondering if anyone knows what is a reasonable price to pay for an Argentine accountant for:
- Obtaining the payment slip for Bienes Personales tax on a property owned by a foreigner (which i can take to pay at a bank).
- Obtaining the document for selling a property as a foreigner.

I have been through these processes a couple of times before and each time had to barter him down on the price, ended up paying about half of what he asked me, but thinking of finding a new accountant who will just give me a straight reasonable price!