HI Michelle
Any of the information for Highest Bidder Sales would apply to high end properties too. The best way to find the deals is networking (not direct marketing). When you do one high end deal, it leads to another because of referrals, then another.
I used a different website for high end properties than my sellyourhousein7days website. Fancier. I got a lot of leads from my website too.
High end sellers are usually more concerned with getting the house out of their life so they can move on than they are with getting maximum price.
Buyers for high end properties are completely different than other buyers too. Mostly cash buyers.