Yes, you will pay a lot to stay at the Cipriani, particularly with a lagoon view, but it is an amazing place.
Other than the prices, there is nothing not to like about the Cipriani. The grounds are extraordinary, while not in Venice proper, all the tourist attractions can be reached in minutes via the shuttle that runs every 15 minutes or so. The hotels location outside the main part of Venice allows you to escape from the crowds seeing the sites and spend a relaxing few hours around the pool.
The food is excellent and the service, overall, is impeccable.
If the prices won't break your budget, the Cipriani is definitely a great place to stay when in Venice.