I know nothing about this site, but I went on a cruise with some friends several years back. The cruise itself was, by far, the least expensive part of the entire trip. Flying to Miami was probably the greatest expense.

If you do the cruise the way the cruise company wants you to, you'll be blowing money in the casino and (especially) on alcohol. The group I was with was composed of particularly ingenious tightwads, so we found out exactly how much water you're allowed to bring (2L per person, or something similar), bought appropriate water bottles, filled them with vodka from Costco, and each took our allowed bottle of wine.

In general, I found the whole thing to be fairly dull, since I don't care for gambling or hanging out at the pool, but it was relaxing, and a great way to get a quick view of several areas in a short time. In my case, we hit Key West, somewhere else I forget, and Cozumel.

These are particularly cheap because they are

1) Per person for a 2 person room

2) extremely last minute (< 30 days out).

Cruises can be a real bargain for sure.

Plus the boat takes you around to different ports. There are "at sea" days and days when you arrive somewhere, get off the ship, walk around, return that evening.

Personally it can be tiring and a typical cruise might have 4 days where you arrive in different places and 3 days when you are just sailing. Some people would like to be in a different place every day. Some people prefer more at sea days. But no big deal it's still nice (you don't have to get off the ship but you sort of feel you should or you would miss something).

The only added expense would be for liquor typically on some cruise lines and almost always what is known as "shore excursions". Like if you wanted to snorkle, rent a jetski or something like that.

As long as the weather is good and the cruise line isn't bottom end it's a good experience I've found.

The inside cabins are the cheapest it gets more expensive if you want a veranda (balcony) or ourside (with a porthole) but the inside cabins are ok.

After all you don't spend much time in the cabin you are on the ship at the pool or the rock climbing wall etc and you get to take advantage of the same things that anyone can. Other added expenses might be internet access or if you want to eat in a fancy restaurant one night (you don't have to the "regular" food is quite good. And it's always available (you can get food at any hour and it's typically free at least on any cruise I have been on).

Since you had no idea you might want to take a cruise, blog about it, and maybe you can figure out a way to help the cruise lines with marketing toward the age group that has never cruised. (I'm serious about that it could be a business opportunity..)

Remember, these prices are per-person. A room assumes 2-person occupancy.

Well, only if you compare SF prices :)

Well, there's more besides the 'rooms are 2p'. It doesn't include food for example... You have to buy that, and it can be pretty expensive because the restaurants on the boat have a monopoly. The other thing is that cruise ships usually have mandatory gratuities that can be pretty expensive.