Both Buyer and Seller, California
I agree with Greg, it might not be a problem although personally, I think having a gas furnace (central forced air system) in the MBR is troublesome due to noise, smell, pests and safety. It would cost about 10-50k to move the furnace and there is no guarantee other problems would not pop up as a result of the move such as dead zones, poor air flow, etc. The builder must have had a really good reason to put the furnace in the MBR, it's not exactly the first choice. I would keep looking but that is just me.