When clients ask Miami travel agent Ralph Santisteban what's included in the price of a cruise, he answers: "Before I tell you what is included, let me tell you what's not included, because that list is much smaller."

Cruises are a great value for frugal travelers, the sales pitch goes, because you pay the fare upfront and everything -- room, food, activities -- is included. Unless you want to watch a murder mystery show over lunch, that is. Or hit the spa or casino. Or drink alcohol, soda or a Starbucks cappuccino.

While many cruise companies long have charged a nominal fee for dining in upscale specialty restaurants, the range of options is expanding as operators seek to draw more guests -- and revenues -- in a tight economy.

Mainstream cruise operators such as Carnival Cruise Lines, Royal Caribbean International and Norwegian Cruise Line say they would prefer to keep fares low and let customers decide where they'd like to splurge rather than include alcohol and fancy meals in the main ticket price.

And there are a host of new opportunities for splurging. The Disney Dream, Disney Cruise Line's newest ship, includes Remy, a $75-a-person gourmet restaurant (alcohol not included).

"What really is driving a lot of the things we do on board is our customers say they want variety and they want choice," said Lisa Bauer, senior vice president of hotel operations for Royal Caribbean.

That cruise line's newest ship is the 5,400-passenger Allure of the Seas, which features 26 dining options. Of those, 12 come at an additional charge.

Even Carnival, which prides itself on affordability with a minimal number of for-fee restaurants, has moved beyond the traditional steakhouse. On its newest ship, Carnival Magic, the line added two concepts: a pub with a private-label beer and a la carte pricing for food, and a for-fee Italian restaurant.

"We try very hard not to nickel-and-dime and to make sure that these options that you have to pay for are few and far between," said Ruben Rodriguez, executive vice president for ship operations.

Updating to stay competitive

While new ships often have the most variety in restaurants and entertainment, cruise lines are also retrofitting older ships to include some of the most popular moneymaking features.

Norwegian's Dawn recently was upgraded to include a Brazilian steakhouse (an additional $20). Royal Caribbean is retrofiting 18 ships.

The push to broaden spending opportunities comes as cruise lines struggle to rebound from the recession.

The world's two largest cruise ship companies, Carnival and Royal Caribbean, both saw net onboard revenue drop by 10 or more percent in 2009, wrote UBS Investment Research cruise analyst Robin Farley in an industry outlook. Both major lines saw a rebound by 2010. Onboard revenues are up in 2011 for Carnival, Royal Caribbean and Norwegian Cruise Line.

Fares haven't budged much in years, said Norwegian's CEO, Kevin Sheehan, and that has made onboard spending more important to the bottom line.

Sheehan said some passengers save up for extras such as gambling, spa treatments, shore excursions and drinks.

Santisteban said he sees it as his duty to educate consumers about what to expect -- and to assure them that they aren't being cheated.

"It's not that the cruise lines are giving less," he said. "The cruise lines are offering more."