lots of variables here. the materials are relatively cheap. the two breakers will be about $10, receptacle/box/wall plate will run you about $5. assuming you can use nm cable (romex), that will cost about $1/ft (assuming both circuits are run in parallel).
the kicker is the labor. is this a finished space, where walls will need to be opened up and repaired? or an unfinished basement? would the receptacle only be 10' or so from the main panel? or is it on the other side of the house and on a different floor? will you do the work yourself or hire a pro? installation could run you $50 up to $1500 or more, depending on your situation.
if you want to go a bit ghetto, you could use the existing receptacles you have in your home and run one of the units off of a receptacle on a different circuit, using an extension cord. if you are brewing in a kitchen of a modern home, it should have two separate 20 amp circuits in the kitchen already, keep the two units on separate circuits.