Rent raise question

[Dror Brumer]

Hi all, 

I have a rental property (Out side of the US ) current rent ( 7000)  was locked at the past 4 years . I took a look at the real estate sites in that country and seeing houses the same as mine asking for 8800-9000 per month. I talked with the tenant he said he will stay if the rent will be 8200 in the first year and 8500 the year after. Mortgage is 7700 (today I am cash flow negative)  If I will take the house to the market it will cost me 8800 for the real estate agent and probably one month the house will be empty so total lost of 16500.  consider I will get 8800 in rent - it will take me almost 27 month of rent to overcome it ( consider 16500/(8800-8200) ) 

It will be great to see what do you think - take a lower rate but save money on the agent and lost of Mortgage payment  or get a high rent that will cost quite a lot of capital today from my side 

[Dror Brumer]

Thank you @Ricardo R. for the help, it sound right and almost the same as I am doing in my rentals properties in the US