Need help with improving changli build

How many tuners on average does it take you to roll 4/5 substat echos with cr/cd on all, roughly 120+ ER, and then some atk%/ damage% rolls here and there?

I am trying to go back and improved my changli S2 R1:

52% CR : 326% CD

120 ER

2200 Attack

30% skill damage bonus

But it feels like i spend like 1k tuners every now and then after farming up echos and then i dont get a single upgrade over my current tuners. I am currently rolling 2 stats at a time strat to save on tuners too. I've built other characters way better in way less resources? Anything I'm missing???