I managed calling, then texting after I called and established they might spk some English.
I found I was usually calling girls advertising 600 grv per hr, but when they arrive they want 800 plus taxi, so 1000grv, which at 40 euros I was happy with. Overnight I paid 2500 grv, so about 100 euro.
I think if the guy is offering to help and he speaks the language, grab it , you'll have better chance I think.
Hope I can find this kind of help next time I go, because I had brilliant time, but maybe I just got lucky.