While some may think it is not expensive , most of us wouldn't spend 1 btc on this . I think that in the long term you would benefit more if you implement some kind of mining fee (reasonable % of coins going to you) into software and give it for free.
With a single rig of four R9 270, you can get 40 XPM per day, you will make your investment back in a week.
So why do you sell it? Buy 2 R9 270 for 1btc and start. You will make your investmet back in a week.