i bought a ticket from Montreal to Kinshasa(congo) with stop over for $3000.

Paris-Tunis $500 (but that was last minute you can get them for $150 low season).

Paris-Istanbul no clue yet but probbly arround $500 too.

Only place i might stay at a hotel would be in Istanbul, Paris=Friend place, Tunis=cousins place, Kinshasa=uncles place.

Then all your expenses in the different cities i usually average between 50-100 a day depending where i am and how much i drink.