Flexible rates? I can find out (9)
I believe the answer is:
ascertain
'find out' is the definition.
(ascertaining is a kind of finding out)
'flexible rates? i can' is the wordplay.
'flexible' indicates an anagram (I've seen this in other clues).
'rates'+'i'+'can'='ratesican'
'ratesican' is an anagram of 'ASCERTAIN'.
(Other definitions for ascertain that I've seen before include "Establish (the facts)" , "Establish after an investigation or study" , "Learn" , "Find out for sure, determine" , "Verify" .)