Decision on final Maintenance amount

I filed divorce on grounds of desertion and mental cruelty in 2019 as my wife left along with my daughter in 2015. I have been paying them regular money close to 30000 per month even after they left. Also I have invested money for my daughter which I'm continuing. There is a concern that my wife may file maintenance case even though contested divorce process is ongoing. It was mentioned by my present lawyer that maintenance amount would be of the order of 60 to 70000 per month based on salary even though liabilities are there. This is really difficult. Somehow I'm not in agreement with him. As I have been paying regularly, is it possible to reduce the final maintenance amount somewhere near to what I have been paying so far close to 30000 as she left on her own will. On what basis usually the final maintenance amount gets decided? Is only salary considered or even liabilities are taken into account? nThanks.