I use the standard cover available from sams club. It's a little big for my 1000. Not a perfect fit. But good enough for me. It's as good quality cover. My first one lasted 5 years. I just bought a new one last year.
So far I haven't found the 9857 cover. And really don't want a $70 cover. Looking for something more affordable. But the main thing is it keeps the water out, since my grill is out in the open.
Greg M is your cover dry inside and what is the price?