If you are 1 of 8 people taking 8 champions and the other 7 are wasting half their coins to reroll 3 stars but stay level 6, that's not a meta. That's them playing wrong. The Void will still beat them.
You'll be taking 20 damage each round if you hold on to 50g until level 8 because you'll have a team made up of 1 and 2 stars vs their 3 star vayne, darius, garen and karthus. You might be able to beat them if you can finish your 6 nobles + Draven build, but if you die before you find Kayle or 2 star your Draven then you are 7th or 8th. If I get the Kayle and 2 star Draven, I will be in the top 4, if I don't get Kayle or 2 star Draven before I lose all my HP then I get 7th or 8th. You underestimate how quickly it takes a player to die in the hyperroll meta.
I watch Scarra and think "why can't I also get opponents who losestreak econ until level 8 so that I don't die before I can finish my noble build" but that's not the way it works. You play the game to counter the opponents you get, not the hypothetical opponents you would be getting if you were in Challenger.
I rerolled at max level 5 times with 62 Coins in hand. I got 2 pages with 2 GP each, and 2 pages with 1. That's how available they were.
That's max luck, man. Even if a champ is uncontested, that takes a lot of luck.
I got a 2* Lucian in play and then 4 Lucians in one page and I was like, OK I guess I'll 3* this. It was the only 3* I got in the past 20 games. I have to hold on to 5 or 6 Nobles on my bench, there's no point trying to 3* if it's just going to take up bench space.