So, if you go: the cheapest way to see many of the fascinating palazzo facades on the Grand Canal is to buy a vaporetto pass and catch the #1 vaporetto at the train station (Ferrovia).

Try to grab a seat on the back of the vaporetto (usually are 6-8 seats on the stern), and then you can enjoy a virtually uninterrupted vista of the Grand Canal (allow about 45 minutes to get to San Marco).