I had one like that with a winch mount on an F250. I'm pretty sure it's a Westin Brand.
I would search Google images for Westin Brushguards until I figured out the model number and what else it would fit.
THEN I would place an ad on Craigslist saying "Westin mdl. XXXX for sale" "Fits Chevy and GMC 1/2 tons 99-2003", etc etc
The more info and specifics you offer, the better your chances of selling it. You'll also do a lot better with a better picture. Lay it on an old bedsheet to get good contrast and make it look a lot nicer. The dark spots in your pic make it hard to tell if it's rusty or not.
Fwiw I gave $900 plus shipping for mine but it included a 12k Warn or Ramsey (too long ago to be sure) winch in working condition.
You need to be priced at 1/2 or less of new to sell quickly.