I normally throw my 2 cents worth in on valuations but this one is hard to tell. If it is truly a 1955 car, which I believe it is and others must as well - because typically 1955 cars get scrutinized on the forum - and it is a mildly more desirable 2 door AND it still has the supercharger intact and probably date coded and viable - then it should be a $20,000 car.
I highly doubt any KFOCI member buys it at that price. There are a few (very few) KFOCI members with big bucks and wealthy enough to buy special cars like this and Darrins, but even they are uber careful to buy the right cars.
Therefore, this is likely a "museum to museum" car, not necessarily meaning it goes to a museum but rather to another monied collector like the present owner. Someone with a broad paint brush as this seller has (we see significant cars in the background but not necessarily tri five Chevys and muscle cars which are in demand).
And those buyers are few and far between these days. Therefore to reach $20,000 + this car needs a very well sorted ebay auction with about 50 photos and a lot of details. I don't think these museum-esqe collectors are browsing CL or have their minions browsing CL, but that is just my opinion.