What other shortcuts is this builder taking would be my question? No amount of concession from any realtor would make up for the invisible shortcomings behind the walls.

Maybe first call the town about a possible requirement for the drain pan. Some things like this are required, like under a washing machine on the second floor. At least in my town.

Heads up: a builder who gets a concession once in the building process is going to find plenty of reasons to demand more.

Call your city's code enforcement office and ask them if it isn't a plumbing code requirement to install a pan under the hot water heater. I believe that is a code in IPC. We always have to put a pan under any hot water heater we install - new construction or replacement - or it will not pass code inspection.

I think I would be looking very closely at the quality of all the work this builder performs. Follow him around like a second skin. While it is nice of your realtor to offer to cover the cost of the pan, that is not the issue here. Find out the code first.

$200 can't be for just the drain pan, they are $20 at Lowe's.

I agree with those about to check to see if the code where you are located requires a drain pan.