I agree with Dougie -- $3K doesn't seem like enough to compensate
for all the extra costs of a much higher-mileage car. The difference in mpg
isn't that great between the two. I agree that it's more fun to drive a stick,
but if you bought the CVT in the first place, that must not have been such
an important factor for you.
Think of it this way -- assume an insight is good for 200,000 miles. A simplistic calculation is $20K/200,000 miles means $1K per 10,000 miles.
But of course the first 100,000 miles are really much cheaper than the
second 100,000 miles in terms of maintenance, so I'd value a 10,000
mile chunk of use that falls in the first 100,000 miles at even more than $1K.
But even ignoring that and going with the simple calculation, the 70,000 mile difference between the two cars is worth more like $7K than $3K.
Steve