So, on average, how much would people say that a PC port of a game would cost? 6 months of time with 5-10 people working on it isn't that much, I could imagine.
Some incredibly crude calculations:
Core programming team:
https://en.wikipedia.org/wiki/Game_programmer#Salary
Lead programmer average salary: $127,900
+
5 x programmers average salary: 5 x $72,000
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$487,900 for a year's work, so about $243,950 for 6 months work. Let's round it up to $250K.
Now for the rest of the team:
As I said the QA guys, or the artists making kb/mouse button art do not work on this straight for 6 months like the programmers do, but what the hell, let's double that $250K to include these guys and make it $500K.
And before one argues that a port might take more than 6 months, what the hell, let's double it again, and say
the total cost is $1M. And that is with a lot of "what the hell, let's exaggerate" concessions. Half of that ($500K) is probably the more accurate answer and that might be only for the most expensive ports.
And that is with US salaries. Port houses like QLOC, being Polish, are likely used at considerably lower salaries, making the cost of porting a game by them considerably lower.
And a specific example:
Revengeance is selling for $24, 70% of which goes to Konami: so $16.8.
If the port's cost was $500K - $1M, then
they need to sell 30K - 60K copies to break even, and that is with the special, lowered, preorder price, soon to change.
Meanwhile a $20 game like Antichamber, far fewer people have heard off compared to a game called "Metal Gear", sells
over 100K copies in less than two months. http://www.eurogamer.net/articles/2013-03-20-antichamber-has-sold-over-100-000-copies-in-seven-weeks
http://www.steamprices.com/us/app/219890/antichamber