The Value of a Chair on a Touring Trip
In my experience (week long camping / bike touring trips), I have never thought "Man, I wish I had a chair." I have often thought, "I have packed way too much stuff."

There are a few things to consider. You have looked into weight and cost, but there is also space and time considerations.


Volume: Do you have space on your rack to put this? How small does it fold up? Does it fit in a bag, or will you have to strap it on top? The surface area can also be a factor: a smaller profile is going to be nice to have on those windy days.
Time: How long is it going to take to unpack this item / everything else? If it takes 5 minutes to unpack this and another 5 to pack it up, then you probably are not going to bother with it for a short break or even a lunch stop.
Utility: How many uses does it have? Do you have other items that would work just as well in a pinch? For example, if you already have a towel, you can sit on that or use it to lay down.


So... as it always is with these questions: it depends. Personally, I just sit on the ground.