Obviously it will take a vet to diagnose whether the issue is caused by liver damage or etc. However it is quite possible it might be only some damage that was caused in the nest or something. This is somethiong that can happen fairly easily. It the beak is malformed due to some physical cause (ie damage or pressure to the beak), then careful trimming--indeed, by a vet-- possibly over a few months' time, can restore it with no problem.
Clearly it's eating okay if that was its spinach. So it's up to you whether to go to the trouble of vet visits, etc. Also, again if the cause was external-physical, then delaying the start of the beak-trimming treatment should not hinder the results. IF the budgie ca survive like that - and it Looks survivable; looks like probably Not causing him too much distress - then correcting the beak does not Have be an Urgent-Emergency situation.
Regarding your Petco. (1) They sold you a damaged budgie. IF IF you were actually determined to return it, the current situation may preclude change-of-mind returns but Not defective-merchandise returns. (Although you might have to escalate to a manager or even Corporate.) But (2) your daughter is likely correct about the results to this intelligent beautiful creature IF you return it. Especially due to the current situation, I expect that IF returned as defective it probably canNot be re-sold.