Jan,

You didn't say when you're visiting Venice and the rates are hugely seasonal. In Februrary this year (obviously no on a cruise) we stay at the Cavalletto E Doge Orseolo, a Best Wern affiliate so you can book it through them. Hotel info at: http://book.bestwestern.com/bestwestern/productInfo.do?propertyCode=98116.

In February (low season) it was about 120 Euros per night for a gondola basin overlook room, breakfast included (on a fully prepaid rate). The location is fantastic...literally over a foot bridge off of St. Marks Plaza. The aforementioned gondoal basin is the one serving the Plaza. The hotel is historic, but nicely maintained.

Their rates can double or more depending on when you go.