I have read up above that you do have 4 graphics card 2 is for ETH and 2 card for BTC? Are you  serious? Even using up nicehash wont really give you a conceivable result even how hard i do think up on the profits but well as you mentioned that you are mostly doing this  because of hobby and doesnt think of about the electricity cost.Decision of selling would be entirely depending on you, since every person do have its own will do decide then criticism wont be given out on what you are calculating on here.