So without my saying what I saw was wrong with the roof, the roofer saw the same thing. The shingles look ok that should be ok another 2-4 year,s which is what my realtor kept saying 5 years; however, it's the deck or substrate underneath, it is rolling with highs and lows/valleys indicating weakness. With all the heavy snow we get that is a real concern. The guy asked me to call him with what the inspector says please, he's curious, he hadn't seen one quite like that in awhile. He gave me a quotes based on the shingles and sealer, and then with new decking too thankfully if the inspector agrees.
I was fortunate to get the guy I got. He is a contractor and as we went around the house to measure and to look at the roof, he showed me some positive things about the house and some weakness that I should take care of. I thought he was trying to sell me something else but then he showed me how to do these things myself, that I didn't have to hire someone. Fortunately all-in-all he said it looked well maintained and that it was a real "gem."

Inspectors coming at the very end of the week though, we'll see.
The astounding thing to me with the new materials, the manufacturer warranties the roof for 50 years and not prorated! It would never have be redone in my lifetime. I thought my parent's roof when theirs was done at a 30 year warranty was amazing, but at 20 years in, the roof still looks brand new. There is no sign of wear and tear. and this the same manufacturer. I remember when younger the roof having to be replaced when I was a kid every 10-15 years; with some technological change, some things are for the best.