Theres probably not gonna be a lot of card types in your graveyard since colorless has very limited access to anything that isnt a creature or an artifact
Ideally, Void will just be the icing on top of the cake, rather than a required extra cost to make things viable
The second side could do some interesting things with cards like Smallpox and Scroll Rack in a 1v1 game
But without those things, Im more likely to end up BG or GU, which tend to play the big game better than GW
And there was a long time that Sram was the best card draw in White since it's mana and tapping free, repeatable and flexible, but no more
As for why the card sold for so much money, the most important reason whether or not it justifies its price is another more subjective question is collecting