For what it is worth, we taken more than a dozen cruises and don't find the size of the ship has much bearing on the cost. Rather, it's the level of amenities and travel style being offered by the cruise line that drives price. There are cruise lines that cater to a variety of travel styles (budget, mid-range and upscale) in just about every ship size. Also, I'm sure you already know that most cruise lines also offer a range of prices on each ship depending on stateroom size, location on the ship and, in one cases, the level of extra services provided for the higher priced accommodations. I'm sure you are probably also aware you can research what cruise lines best fit your budget and travel style at cruisecritic.com