Should just ask the owner to really go out there and check on paint price nowadays.

The market itself is competitive, good quality material and workmanship do costs a lot more than inferior/normal quality products/workmanship. Also, If the owner hire different contractors for different jobs then the hired contractors should know when is the best time for them to come in, the painting contractor should also advise the owner beforehand. Only start the work when both seller and buyer has consensus on it.