$92,000 Net revenue - $52,000 Variable expenses = $40,000 Contribution margin. This ratio is only used from the perspective of deriving the lowest possible acceptable price for a unit. In reality, a variety of other pricing concepts can be used to establish higher price points for products.
Steam OS is possibly the best, most known and used cross platform Linux gaming distribution based on  Debian Linux, it is an assortment of numerous entertainment software, you can think of it as a complete gaming platform for Linux.
Windows tends to be the best operating system for gaming, though you may initially want to choose Windows 7 over 8, as some of your older games may have compatibility issues with the new system. This will not be an issue for any games released during and after 2013, however.