Coloseum Pay-Wall

This is not my experience. I’ve been levelling regularly and have begun reaching t3 on the bosses. 

I've had relatively steady progression, but I have used crystals to get more Era Level currency at least twice.  I have not bought the Episode pass this month.  

I think you're forgetting that early in the STLuke era things were much the same. 

Early boosts to the first toon of each era helps you cascade forward and stay on a good developmental path. That initial boost costs a significant amount, but less than 4k crystals. 

I spent less than 10k on Kleya (6k for shard pack and prob ~2.8k on mats/credits but I'm not sure exactly, it could have been more) and 6k on Vel (shards only). Right now I'm Lvl 29/27, and I have the mats to be 29/29, just waiting on a few more credits which come quickly at the end of the Episode track. 

That might be beyond your budget, but I promise that with the right boosts at the right moment, you can get yourself rolling. The hardest part will always be when you reach a new boss tier and are trying to hit 10%. If you're stuck there and you have crystals, you might consider buying mats. (Shards don't help. I buy them for other reasons.)

If you're stuck somewhere else, why not tell us where you're stuck % wise, on what tier, and what the levels of your toons are, and we can maybe help? Getting stuck temporarily is fairly normal, but getting stuck for more than 5/6 days is definitely not. If you've been stuck for 5 days, we'd love to help get you unstuck.