For reference my car’s factory specs include...
2012 12c coupe, ~$310k msrp, under 19k miles
Clear headlights without fog or mold
Carbon interior, exterior, and engine upgrades
Carbon ceramic brakes
Black alcantara/leather interior, orange stitching
Variety of other misc. upgrades
19 months left on ESC
Annual service completed 11/2018
That's a great spec. EDIT: I see that it's a very early car.
FWIW, I think it largely comes down to the buyer’s wants in the car. A random enthusiast will just want a 12c and be less scrutinizing of the color, add-ons, brakes, etc. A more particular individual looking for volcano colors, CCB, carbon everywhere, etc. will be far more willing to pay more to get what they want.
I agree to some extent, although the sheer number of 12Cs (especially 2012s) does pull values down. IMO, cars without nice options (including colour) just don't sell.
A local dealership appraised my car and said I could expect up to $140-150k in the private market. They offered ~$125-130k through consignment or ~$115-120k for a trade-in. Said it was a bit of a unicorn and required the right buyer, but it ticked all the right boxes.
Bite their hand off - $115-120k trade-in is unheard of (on a correctly priced purchase). I would say, if everything else is positive, $110-112k in a private sale. We should talk if you're not offended by that.
We also looked at the cars on the market and mileage did not seem to matter much. The two highest priced cars had a more than 10k mile difference on their odo’s. Just depends on the car.
Asking price means nothing. That appears to be the justification used by sellers with cars that don't. There's not a lot of point in pricing against ones that haven't sold, IMO. Higher (not really in absolute terms, 20+k) mileage cars are very difficult to sell, and appear to go under $100k.