There's no getting round the fact that Bermuda ain't cheap. Bermuda's high cost of living, the result of most goods having to be flown in from the US mainland, is reflected in hotel room rates and restaurant menu prices. Even grocery costs are 50% higher than in the USA.
This is not the place to come if you're watching your budget, since you'll be hard-pressed to find a double room under US$100 and the average room price is almost double that. If you plan to stay seven days or less, it's worth looking into package deals that incorporate both airfare and hotel accommodation.