Ebay, Head-fi buy sell trade, and avexchange on reddit will be the places you want to look unless your looking for brand new. Either way, its a hunt for when or if they go on sale new or used. Good luck hunting.
The FH3 used sells pretty fast and i’ve seen them for around 110 I believe.
You can also check out the buy sell trade thread on hifiguides and post a WTB for those items as well.