Domestic (local) -> Domestic (further away) -> Cruises -> Lower and medium end travel to Caribbean and Europe -> Medium to higher end traveling to Caribbean and Europe -> World traveler
Some people stop along the way, either from budgeting issues, time availability, get nervous about not having your hand held during international travel, etc
But in your example - you almost certainly had to be in the entry level room with no view, drank zero/no alcohol, didn't do any off-boat tours, didn't use the internet, didn't tip much, etc, plus not including airfare + hotel on front/back end of trip by port to get to $800 (or you risk missing your cruise if flight is cancelled) - or you aren't including those in your $800 - all that needs to be added up and compared to other alternatives. Cruise ships love breaking it down this way because it gives the illusion of being cheaper than it really is
The last time I priced our a cruise - the cheapest I could find for my wife and I with 200+ sq ft, a view of the ocean, alcohol included with some internet and tips, not including air, hotel b/a, or tours off the cruise, was about $3.5k for the cheapest 7 night cruise I could find. For folks willing to stay in a 120-145 sq ft room for 7 nights and don't drink much alcohol, more power to you. I haven't been able to deal with that since I turned 30.
Lastly, yes anywhere you go you can find some privacy, but the popular areas are popular for a reason and are nearly always very busy on a cruise. Not true on most resorts.
Actually, we had a lower deck room with a window. I really don’t care about the room much. I’d be content with one over the rudder, so long as it was dark. We only went there to sleep. We took Amtrak from D.C. and the caught a cab from Penn Station in NYC to the terminal on 12th Avenue. After the cruise, we stayed in Manhattan for a week and visited the World Trade Center one night. We stayed on the observation platform on top about two hours, watching the traffic flowing up Broadway and enjoying the smell of salt air off the Atlantic. That was the last week of August, 2001.