Okay so pumpkins are cheap if they are small or scruffy or raggedy. A lot of the raggedy is external and can be removed. Still it means a pumpkin may vary in price from like one pound to three pounds. You can be cheap pumpkins and they will clean up to decorate .
You either vinegar or an organic salad cleaner and kitchen roll or cotton wool.
Gently coax off each mark even what look like scratch will come off.
Get a cup of tea it’s not a rush job it’s like waxing a car.
(Some people have time, some people have money!)
Then wipe down with water. Let dry.
Take an old brush and a high pigment gold acrylic paint and gently stroke down from the top of the pumpkin.
Do this top down gently skimming the top for a gold aged look.
To remove the gold paint remove with vinegar and cotton wool as before. As it is non toxic acrylic it will stay but be removed if you wish.
If you paint the whole pumpkin , you may have problems, either burning or eating it.
It is very effective and cheap, instead of cutting off the top just carve a small window instead in the middle and a small hole off centre at the top to let out smoke.