Slightly tainted but dear in price (4)
I believe the answer is:
high
I believe this is a triple definition!
'slightly tainted' is the first definition.
'high' can be an answer for 'tainted' (thesaurus). I am not sure about the 'slightly' bit.
'but' acts as a link.
'dear' is the second definition.
(thesaurus)
'in' is a link.
'price' is the third definition.
(thesaurus)
Can you help me to learn more?
(Other definitions for high that I've seen before include "In slang, under the influence of drugs" , "Tall, elevated" , "having senior ranking?" , "Important; drugged" , "State of euphoria" .)