If you’re talking about a barbecue grill, they now have high-heat resistant spray paint, in cans, that you can use to paint a grill yourself. It’s available at Wal-Mart and most hardware stores for about $4 a can. As the previous reply said, the auto paint shop will be expensive, and the suggestions to pay or barter with a friend or relative to do the job for you would save you lots of money. Check this spray paint out–hardware store clerks are always happy to advise you.