You may want to market to listing agents who don't want to handle buyer calls. I looked up the top listers in my company who don't have teams. Many list HUD and Bank repo homes.
One asked if I can place my sign rider on all of her signs so she doesn't have to answer questions or take the calls. She didn't want this on all listings, but on the ones that will take longer to sell. She also thought it was ok for me to market the listings on my website as long as it had the seller-required information and named her as the listing agent.