I've always heard photographers that praise a photographer for collecting either a 35/50/85 or 24/50/135 lens collection. Those are really really great lens and I've only got to spend 30 minutes with a 50 f/1.2 and I ultimately fell in love with it.
Is there a non-L prime trinity out there that offers the best images?
Like this is what I'm thinking, if I were to get the non-L versions of the 35/50/135 lens is that a good enough prime collection?
The Sigma 85mm is an obvious choice, though at its price point and quality it really plays with L glass. 35 f/2 / Sigma 85 f/1.4 / 135L would make a pretty solid budget trinity.
The only issues with your proposed trinity are that 35mm and 50mm are pretty close together (if you have a 50, you might start looking at 24mm instead of 35mm), and there's not much point getting a budget 135 (the 135L is one of the best values in the lineup).
If you can live with manual focus, Samyang's lenses are a steal at the wide angle.