i replaced one of my painted door trims for about $65 from Honda...it came prepainted and matched perfect...so i think you could do that for under 300 if you want to avoid the bodyshop and DIY...
Unless you can sell your old ones, I doubt buying new ones would be the cheapest route.
As for price, like darkside said it all depends...where you located? Find a small shop w/ low overhead and good rep.