You say the delam area is only 6 in in dia. If you can describe where it is in relation to a window etc, you might get better answers. If you coin tap the area around the delam you can hear where the outer skin is separated . If it is below a window and you can see where the window leaked you can reseal the window and re bond the outer skin while the window is out. I would use this as a point of negotiation on price knowing that it would take a half days work to fix it. I would not be afraid to fix a 6 in area, complete side wall areas I would pass on.