Bottled gas, at best, missing the precious stuff (4)
I believe the answer is:
gold
'precious stuff' is the definition.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for gold that I've seen before include "One of the Magi's gifts" , "gift from a king" , "first gets this?" , "Valuable metal" , "bull's-eye" .)