Actually, I don't see what problem is there to make this a timed permanent with a lower cost.
Healing? Ok, but definitely not the point of the card - see Purify. This helps the card to become less of a SoG's little brother.
Quanta and hand protection? Let's see the cards affected:
- Discord: the main problem, the main issue. You need you Sanctuary out fast - hence low cost - for it to be effective, and you don't need it for long, especially if you can chain them. You just need 5 turns to get your favourite rush started, you can beat entropy war decks with 5 turns of protection, possibly more. And if they want to destroy it, well, no BH for them - or an instable trio which is IMO worse.
- Pest: steal it. No problem. Good counter, not a shutdown.
- Black Hole: not that much of an issue really. Wait for Sanc to go down, hit hard with 3,4 BHs in a row. Hit with BH a rainbow before it gets 4 light out. Golden.
- Silence: good counter, but not a destructive one.
- Nightmere: needs to be buffed anyway.
So what's the problem with 1-2 cost and timer?