Summary. You don't have to stay in the famous (and expensive) towns of Bellagio and Varenna in order to enjoy them. Instead, stay in Como and take the "fast" Ferry to Varenna, hop off and tour the town by foot. Jump back on the Ferry and head over to Bellagio. Depending on how much time you have left in the day, consider taking the "slow" ferry back to Como, which makes 10 or so stops along the way as it cross-crosses the Lake to stop at all the lovely Italian villages that sit on this beautiful lake.
Ferry. Even if you do not have any particular destination in mind, the Lake Como Ferry system is a fun way to see the towns that sit on this gorgeous Lake. Ferry tickets are very inexpensive. Before jumping on the Ferry, be sure to walk Como's gorgeous waterfront.
Varenna and Bellagio. If you are looking for a high class vacation destination, these two towns should be on your list. They're gorgeous of course and we can see why Hollywood stars often summer here in mountain villas behind the towns' centers. While we ate our picnic lunch rather than pay for a pricey meal out, we did of course stop for Gelato while in Varenna.
On the way back to Como, we took the "slow" ferry back to Como, which makes 10 or so stops along the way as it cross-crosses the Lake. We enjoyed the long route by grabbing a shady spot on the ferry and watching the Italian towns and luxury villas pass by. It also was a nice opportunity to have some quiet time after several days of travel.