Drink became more expensive? That's a bloomer! (3,4)
I believe the answer is:
tea rose
'expensive? that's a bloomer' is the definition.
I can't judge whether this defines the answer.
'drink became more' is the wordplay.
'drink' becomes 'tea' (tea is a drink).
'became more' becomes 'rose' (eg a number which rises becomes more).
'tea'+'rose'='TEA-ROSE'
Can you help me to learn more?
(Other definitions for tea rose that I've seen before include "Scented garden flower" , "Flowering bush" , "Eats roe (anag.)" , "Bloom" , "Garden plant" .)