You're right, all these aspects are important. If you add all these costs, such as electricty cost (3W * 24hr * 31day / 1000 * 0.15$/kwh ~ 0.33$/mo), it's hard

You're right, all these aspects are important. If you add all these costs, such as electricty cost (3W * 24hr * 31day / 1000 * 0.15$/kwh ~ 0.33$/mo), it's hard to be both profitable and competitive. I'd pay maybe 2 or 2.50$ / mo, but I'm probably not a good example because I like running my own RPi at home and be able to tune things. Nice project anyway, good luck for staring your service!