Don't be jealous. Just kidding. Just do it. Easier said than done, but I recommend it.
And you nailed it. It is considered a crossing in that it's New York to Southampton, or vice versa. Those who know and love this voyage would bristle at it being called a cruise. It follows the traditional historic route of its Cunard predecessors. This is my third crossing and fourth time on QM2.
I cut out a lot of things in life. I hit up BK on Whopper Wednesday, for example!
Say you're heading to Europe and staying a while. Compare a nice enough cabin to outlays for one-way airfare, lodging for 7 nights, your daily meals, and that you don't have rental car costs and utilities. It's not that much more. You'll have to get an internet package. I also participate in the tipping package and give extra to the stateroom attendant and the dinner waiter and second person. I don't buy alcoholic drinks and I don't go into the casino. I bought a mug and a t-shirt this time ... usually stuff like that.
I do have some CCL stock I bought a few years ago. The 7 day crossing gets you $100 in credit.
This crossing runs deep in my family. I made 2 round trips on then active Italian Line as a kid. My parents and some of my relatives did it more often than that. Italian Line still called it a transatlantic crossing, but they had stops. Often, from NYC, it was (1) Portugal: Lisbon, (2) Spain: Algeciras/Gibraltar, Barcelona, OR Palma de Mallorca, (3) France: Cannes, and finally (4) Genoa and Naples. They did drop off and pick up passengers at these ports, so people from 4 Southern European countries used their ships to immigrate or repatriate. In port, we usually took the 4 hour motorcoach tours. Lisbon was my favorite port. My parents said the food on Italian Line was top notch, but it was definitely Italian-centric and only somewhat international. The cabin attendants made us these delicious panini with prosciutto, cheese, etc. when we kids asked for them as snacks. You will never forget crossing an ocean as a child.