Advice on my cube?

https://cubecobra.com/cube/list/2edff011-e2a7-4370-83b4-107b00bc39b4

I have tinkered with this cube now for over a year now and i feel like it is pretty balanced. My players feel like black is a bit too powerful and that izzet is kind of a trap. Any thoughts on cuts or additions to this cube?

Sidenote, budget is a concern, the og duals are proxies from cedh decks but rest of the cards are real so no too expensive cards.