Starting salary for phd graduate

It depends on the firm. MBB hire PhDs/JDs/MDs at post-MBA level so the salary is same as MBA graduates. They are hired at McK at associate level and at BCG and Bain at consultant  level.

The salary depends largely on the office and geographic location. For example, in the US, it is around $150K + up to 20% of base salary as performace bonus + sign on bonus.

Masters are hired at entry level read Business Analyst at McK or Associate at BCG but at a higher cohort than an undergrad. So the pay is a bit better than undergrads.

Tier-2 firms (OW, BAH, RB, Strategy&, etc.) tend to hire PhDs at a lower level than MBA grads.