I moved Giroux for Honka, Pulock & N. Ritchie in my league in sig. With G. there's always a chance you eat this deal the next two years, but after that Nylander & Drouin will be into the 60's on an annual basis. I don't see Giroux really eclipsing 70 again, or if he does I don't think it'll be more than a one off season.
If the other owner is willing so quickly to add A. Ny to Drouin, there might be more room to squeeze extra. As it stands, I'd still say yes and pull the trigger. I'd tell the other owner you're really hesitant to let him go at such a discounted price - get more.