We really enjoyed Venice. You do have to think differently. Coffee in St Marks Square is expensive but if you view half the cost as allocated to renting a seat with a view of the square then it feels a better price. Find a small restaurant in a back street for lunch or dinner and prices are verging on reasonable.
When we were last there, a Gondola ride was €85 for four of us but well worth it.
A water taxi trip to the airport from the city is a brilliant experience - like being on a highway of fast boats.