I am having my 23 yo house stained.

He pointed out that several windows had damage to the bottom molding that
holds the glass in, and to the sill below it. The moldings has finger
joints that are falling apart. The sills are flat when they should be
angles, and so they have held water and become water damaged. He wants to
grind them down to a proper angle and put wood hardener on them.
When he gave me the price he saw 6 like that and included repairs in the
price. Now he says another 12 are bad and should done, at about 90 minutes
each.

I know absolutely nothing about home construction. Does this make sense?
Is 90 minutes to replace the molding and repair the sill reasonable. It
sounds high, but never having done it...