Paint job

Ok i know for a fact black is the hardest color to paint a car..at least cost wise..for average colors but i wanted to ask about how much it would be..estimated for an old car around the size of a challenger or maybe charger...would be better...uhh and also what would be some color prefrences for an old muscle car?

Colour.....for maximum value, its best to paint it the original colour......get the paint custom mixed to the original tint.
If the original colour is puke (seafoam) green, as in my case, paint it another colour offered by the factory for that year.

Be careful of metallics. Modern metallic paint looks different than the originals because the metallic particles are different, even if the colour is the same.

If that won't do, paint it 'resale' red.

Otherwise, paint it whatever you like.

The cost of the job is far more dependant on the preparation and labour to prepare. Thats where the money is and where a good job is distinct from a poor one. For materials expect to spend $400 to $1000 for something decent and allow at least $400 for good prep work, if no significant repairs are needed.