I got a set of all 40 when I traded in a mess of cards to a game store a couple months back.
I'd say that waiting a few years will do anyone well, as the supply becomes more scarce, and with more and more players entering the game, more people will want these lands.
If Erebos' agents are coming to her, I think while she might have died, there are still plans for her character as a returned or as someone for Erebos to use against Heliod.
G: Zendikar
U: Ravnica
B: Phyrexia/Innistrad
W: Theros/Innistrad
R: Tarkir
Also flesh to dust is so painful to see, so very painful.
I'd say that waiting a few years will do anyone well, as the supply becomes more scarce, and with more and more players entering the game, more people will want these lands.
They wouldn't offscreen a walker like Koth. He's definitely still around.