Hi Steve,
Price the parts needed. Double the total parts cost and add it to the parts cost for the ballpark total. It is a very small job that a handy-man or contractor would probably over charge you for(get three separate bids). If you can glue or screw pvc pipe together you can do this project in a couple of hours. Build the the manifold as one piece and connect(glue) to your system and copy how they have the wires connected from old to new. Done deal. Go out to dinner on what you saved. Aloha