Varenna worth paying a premium over Bellagio/Menaggio?

Varenna is easier because you can take the train directly to it as opposed to train and then the ferry when arriving and departing. For me, it would depend on the circumstances of arriving and departing. How many nights are you staying? Will you be arriving off an international flight?

It all depends on what you want your lake experience to be. Getting around the lake is far easier via Varenna than from Bellagio. More frequent ferries & easy train access are the biggest two reasons. I've never considered Varenna as an economy stay. We typically spend only 8-10 hours /day in our hotel/apartment/rental, and that is mostly sleeping or dining. There are plenty of spots where you can enjoy tremendous views in Varenna and Bellagio that are not from your accommodations. But if that is the most important thing for you, then go that direction.

We loved our stay in Varenna at this apartment. View of the lake, and has a patio, and access to Bao Bao Beach across the street. See if this fits your dates and budget: (we originally booked thru booking.com, but the rates are much lower here:)
https://www.varennaholidays.it/rentals/apartment-perledo-casa-paola-261492.html

We had a lakeview room at Hotel Beretta. It was close to the train and the ferry, and the price was reasonable. We hiked to Castello di Vezio where the view was amazing.

The entire area is beautiful and one of my favorite places I have ever visited. If a view from your lodging (and patio) is the most important criteria for you, go for Bellagio (I just changed reservations in Germany for the same reasons).

Any of the 3 towns would work for me (I’ve stayed in all). They are all quaint and only minutes apart via very frequent ferries. If you want to avoid people carrying the blue and yellow books by Rick Steves, avoid Varenna.

I would stay in Bellagio over Varenna every time, regardless of the cost. Although the train is on the Varenna side, there are way more ferry and boat options from Bellagio. The views from Bellagio are better as well. More restaurants, etc.

I am going the third week of September and there seems to be something going on because on either side of my dates there is plenty of hotel availability and reasonable prices, but of course on my exact dates prices are higher and most hotels are already booked. First world problems. :-)

Interesting, April! My dates are Sept 10-14 and it seems like everything is pretty booked up. Is that the week you're talking about or were you looking at the week after that?