The portals that sell it are going to take a hefty cut before the developer gets anything.
I thought the portal sales where a seperate accounting item?However I do feel that 900USD is not an accurate account of all the expenses, and even if it is, the gross profits only make up an average of about 25USD an hour (depending on how many days where 4 hour days, and how many where 3 hour days).
I suppose you could live off it tho' if you like spagetti and ketchup.