okay so my dad just sold me his 1984 pontiac firebird and im wondering how much its really worth its not listed in KBB cause its so old. but anyway its got power windows, convertible T top, 55,000 miles and a $3000 black paint job from 1999(its been in the garage for most of its life) it runs great and has a V6 engine what would be the approximate value of this car?