Sam, that's the retail value buying from a dealer, not from a private seller. You're in car business, unless you can put it under the business as a used car dealer to sell your X, the private party value is more accurate.
Regarding the "Supercharger" badge, it equals to "false" advertisement, since your X isn't supercharged. It might make a potential buyer thinking "what else could he lie about the SAV?" or "He might had it supercharged before and race the sh*t out of it"
Anyhow, it's your X, keep/put whatever you want on it.
Regardless, GLWS.

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