ive been seeing the same while i track the balconies on mine, one day there was 16 the next 32. Today theres only 9 (hopefully for my bids sake thats wrong).
did another mock booking, one day there was 105 balconys available 2 days later theres around 3. Looks like im boned for winning an upgrade.
Edit: nevermind 99 available 40 days out
Theres 120 or so balcony cabins left on my sailing around 40 days till, called ncl upgrading from an inside is around 900$ more, so im going to roll the dice with my bid a little above min. Seems like alot of cabins left.
I did a mock booking just now and its around 600 different which will be higher than my bid, still not bad. Unless they offer me a better price over the phone, maybe ill try it just to see.