Last year I bought bale of mix from a nursery- I think it's a good value that way and feels like money in the bank.
For some plants, I use a lot of fine bark mulch in the mix. I even had good results with a Sanseveria in straight bark.
Downside is, if the bark chips get dry, they take some effort to rehydrate. And I think I was leaving the baled mix too loose, not pressing it in quite enough, and some plants tended to be too dry.
I do recycle used mix into new outdoor pots.