Presumably US-based, so AFKL shorthaul isn't going to be 5 euro per XP when positioning is considered. Though that also means that FB Gold won't be worth as much beyond mileage earn, unless you fly DL to Canada/Mexico/Central America/northern South America.

The 80 XP in this situation would at least get you another year of Silver (whether by giving you 70-ish XP which will combine with the card and your travel pattern to give you another year or making Gold and soft landing to Silver).