[typing]

Sorry, what I wrote is if you're an acctual Manga-Ka

If you're just starting then you're looking at self publishing which is the Doujinshi racket. In that case you make what you sell after paying your own printing fee.

At Comiket the average comic sells between 200-500¥ (2-5$) the average unit is about 100-1000 comics depending on the popularity of your circle. The higher your print the less the comics cost to print so a 100 print is usually 500$ or so (for 20 B&W pages and colour cover) selling at 5$ you break even, a 1000 print is about the same price, selling for 5$ you make about 24,000$ but the key is to sell them all. That's the tricky part as nothing is worse then getting 1000 copies and then only selling 10.

Then you have to calculate your costs, time to make the comic, materials used, paying assistances, ect ect ect. In the end your profit is compleatly dependent on yourself.