We can use should have + pp to express our regrets about things that didn't happen in the past.
I should have talked to him about the car. (I regret, that I didn't talk to him)
In the other words it would be more beneficial to me to talk to him. Could we express the same idea with the be better off structure? As far as I understand, the structure's expressing that something would be beneficial to me.
I would have been better off talking to him about the car.
I should have been better off talking to him about the car.