So work travel policy apparently allows me to purchase Y class fare (work travel dept even proactively asked me if was going to upgrade with miles!)

However, I called Delta, and there is no space, so waitlisted. As a Plat status, what's my chance on this clearning? Flights are SEA-AMS and back. Does upgrade with miles come in at a higher priority than GUCs?

And does anyone have an idea on the cash co-payment? Delta can't give me a number until the flight is ticketed...