When trying to determine how much cabin you can afford, do not forget to factor in the cost of the rest of your trip. If you have to spend a lot on airfare, pre-cruise hotels and activities in port, you might not be able to afford the fanciest suite; if you are using frequent-flyer miles or do not need to book a hotel, you will have more money for cruise fare; the money you save on airfare can be used to spring for a nice stateroom. Or, look for value-added perks from cruise-line and travel-agent promotions. Offers for complimentary onboard cash, prepaid tips or included airfare can free up some money to pay for other vacation expenses.
Pay attention to the unique cabin setups on your ship, as they are not all created equal. Disneys four cruise ships, for example, have large standard staterooms designed to accommodate families. Even inside cabins may have a sleeping section that can be curtained off from the living area along with a split bath system. (One bathroom has the shower/tub and sink, another a toilet and sink.) Carnival is also known for having larger-than-average standard cabins, while Silversea, Regent Seven Seas Cruises and Seabourn ships feature all-suite accommodations. Norwegian Epic cabins sport the "new wave" design, with curvy walls and separate rooms for showers and toilets; sinks are located in the main cabins. As mentioned earlier, cabins at the very front and back of a ship often have different layouts than the cookie-cutter cabins that run the length of the ship.
For some reason, most cruise lines assign their nicest and most expensive cabins to the highest decks, usually just below the pool deck (most likely because if you have a window or balcony, you have a more sweeping vista). Still, it is the pool deck that often causes the most noise problems, so if you do not want to hear scraping chairs at the crack of dawn or yee-hawing pool parties until the wee hours, go down a level. In fact, when it comes to noise, the best bet is to select a cabin that is both above and below other cabins.
Having a personal butler can be a wonderfully pampering experience, and some cruise lines include the butler service as part of your fare when you select a suite or "concierge level" cabin. Look carefully at the difference in the cruise fare, and decide if it is really worth it. Beyond that, look at the services that are offered; some cruise line butlers really do provide extra value. For instance, some can bring you room service from hard-to-get-into alternative restaurants, refill your mini-bar to personal specifications, and serve in-cabin meals course-by-course. Butlers can also unpack and repack your bags, draw rose-petal baths and assist you in preparing in-suite cocktail parties.