It is too broad a question. The location is a huge factor I guarantee rent Rent in NYC requires a much higher membership fee then rent in Gainsville.
Quality instruction, mat space, does the owner own the area or does he rent from another owner, number of students.
I think the question should be how much a gym should cost to you?
Then you can factor the value BJJ has in your life which could be from very important to very little, your income and costs, extra costs GIs transportation etc.
For me here in Venezuela I dont want to pay more then 500BSF a month depending on your exchange rate it will be either A= $50 or B=$10 a month.
Space is good, quality instruction is decent, level of instruction, speed, training partners I dont think it is worth more then that. Plus Venezuelan salary terms anything higher it would be too much. Everybody I know doesn't like to pay that much.
When I go to London, I am willing to dish out up to