A couple of chips, maybe (3)
I believe the answer is:
'a couple of chips maybe' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bet that I've seen before include "Wager, speculate" , "Speculation" , "22 across will accept one" , "'Stake, wager (3)'" , "Money risked on a gamble" .)