Mining hardware like this will never pay its self off. mining litecoin is not profitable unless you have a personal mining farm. if you are part of a mining pool, then you will never make enough money. if the difficulty remains the same, 3 r9 290x's would take around 3 years to pay them self off.You only make a profit if you are buying the cards for gaming, and you do not pay for electricity, then what ever money you get, is a profit. If you are only using the system for gaming, then it will never pay its self off, the difficulty will increase beyond what the GPU can handle before it comes close to paying its self off. Currently the only way to make money, is to start your own mining farm (requires hundreds of GPU's working in order to have a chance at mining a block on your own).