Let's assume your mining rig costs $1 to run, generates 1 FAKECOIN with a current value of $.90. That first month you pay $0.10 out of pocket for 1 FAKECOIN. If you had just purchased 1 FAKECOIN, it would have cost you $1. 10x the cost. Like a startup, this is not sustainable without external factors changing. "Just buy it directly" requires a separate income.