Hi number6,
The mix of fruit,berries,nuts etc is all fine for your grey.I agree buying the ingredients separately & making your own is cost effective, doing it this way you can add things you know your bird will eat & there will be no wastage compared to a premade pack they may contain certain items your grey doesnt like.
If you buy fruit/nut mixes from the shop you can always add items like dried pumpkin seeds etc..
Do you have health food stores near you ? These are great for getting bits to add to your mix.
Wasabi is a member of the cabbage family. Known as Japanese horseradish, its root is used as a spice and has an extremely strong flavor. Its hotness is more akin to that of a hot mustard than the capsaicin in a chili pepper.Wasabi coated products are fine in moderation.