Can you estimate how much it will cost to prepare an area approximately 170 sq mts and lay it with concrete sufficient to use as a walkway?

I can tell you that the going rate for 4 inch sidewalk is about $ 5.00 per square foot and
$ 7.00 for 5 inch sidewalk based on bid prices at MD State Highway Admin. These sidewalks are normally 4 feet wide, so I don't know how that might compare to your project.