I wouldn't mind a device that could do breeding, but what I would really want is a cloning machine. Put in seed bags and other costs (determine as required by balance) and then provide it power and time, and it will clone seed bags.
that could be quite... unbalanced for the better crops that give things like iron and such.
a fair price would be that it'd require a very small amount of liquid UU. it really doesn't use much, but still requires some infrastructure to be set up. sadly it would mean that that part of crops would become end-game