Very few ships actually have cabins dedicated to solo travelers. These will have sleeping space for one and can be quite small. The studio cabins on select Norwegian ships are the most famous example of this: The 100-square-foot staterooms each contain a full-size bed, nifty lighting effects and a large round window that looks out into the corridor. If you are a solo traveler, you will want to price out the cost of a solo cabin (usually somewhat higher than the double-occupancy rate of a similarly sized stateroom) compared to the cost of paying the single supplement (an extra fee tacked on if there are not two people in a cabin; the price can come out to as much as double the regular rate) for a standard cabin. And book early, as solo cabins sell out quickly.
All cabins come with basic amenities, such as the services of a cabin steward to clean your room and turn down the beds, soap and shampoo in the bathroom, individual climate control, etc. But certain categories of stateroom come with added perks. Suites come with a variety of extras and privileges, everything from priority boarding to in-cabin bar setups. Spa cabins will offer spa-related perks, such as yoga mats in the cabin or a fancy showerhead; concierge-level cabins will give you access to a concierge and niceties like afternoon canapes; and even solo cabins might offer extras, such as the use of an exclusive lounge. How do you want to be pampered on your vacation?
A concierge can take care of all those annoying practical matters you need to tend to on a cruise: making dinner and spa reservations, booking shore excursions, making requests of the front desk. Their services are included in the price of many suites, and on some ships the concierge has a desk in an exclusive concierge lounge where suite guests and high-level past passengers can snack, drink and relax in private. Concierge-level cabins may also come with in-cabins amenities including welcome drinks, fruit baskets or afternoon canapes.
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.