Also, as someone mentioned, purchasing a full fare First/Business ticket can be very expensive. If you are flying from New Jersey to MCO, I would say 'don't bother', and better spend the money on an upgraded hotel room, etc.
And please don't expect an upgrade due to honeymoon - there are very few seats available for upgrades anymore, and the airlines will choose to upgrade their elite members if they DO need to upgrade anyone.
The only time that I see operational upgrades is on international routes when Economy is oversold, and Business/First still has vacant seats. They will look for frequent flyers first, and then upgrade those on special occaisions, etc. For instance, a Lufthansa Business class seat on the route I fly regularly is about $6,000; Economy is about $1,200. For the extra $4,800 one has a lie flat bed, video on demand, three meals on china, ammenity kits, etc. For me this is definitely worth the extra money or miles when I am flying 14 or more hours.