Keep in mind that the free basic install includes installing lines for 2 receivers. Any additional lines cost $50 each. The installer could charge you directly for the extra lines if he has time to do it. I talk to our installers a lot and we constantly remind them that they will only get paid for doing work that's on the work order. Your work order would state to run lines for two DSR505 receivers and that is all he will do. The installers are really busy and they plan how many installs they can do in a day based on what is on the work order. If you ask him to do extra work that he did not expect, he might not have the time so you might have to schedule another day for him to go back.
To make sure things go smoothly, I would recommend calling star choice and have them update your work order if you do indeed want to go ahead and run extra lines.