Tried to PM you but looks like you don't have sufficient privileges....

If you're open to it - in the early spring I'll be posting a well maintained tiptronic C2S w/ ~50k mi for the price of a similar narrow body manual car w/ 75k.

 

You might find this chart to be a good starting point. I put this together during my search last year. The data points represent actual selling prices, not list. You'll find list prices have a much wider spread. I didn't collect data on 2's and 4's but they *seem* to be 15 to 20 k less than an equivalent S.

 

What % off of those prices do you recon tiptronics go for?
There's a C2S last year with 85k mi that sold for 58 IIRC. How does that align with your numbers?

 

My guess on the Tip penalty is $15K. No objective data to back that up.

The formula for the straightline fit in the chart is $111K - .57*k-miles. Using that, an 85K-mile "S" comes in at $62.5K.
Many variables to consider, so use it as a starting point or "sanity check".

 

Maintenance on cab tops can be expensive...new cables, top latch motors, new canvas top on average every 7-10 years - I got 17 years out of mine with patching from time to time, circuit board controller failures, micro switch replacement....the design was not great with this top....my personal experience spending $ 7,000 over 20 years which includes 3k for new top 3 years ago...always something with the top...