How maintenance amount is decided by court?

A husband and wife were married for seven years. Due to matrimonial differences, the wife left the matrimonial home and has been living separately for the past five years. There are no children from the marriage. The wife has been unemployed for several years, is a science graduate, and does not own any residential property. During the marriage, she contributed approximately ₹5 lakh towards the renovation of the husband's ancestral house and bore her own basic living expenses. No maintenance has been paid by the husband during the five years of separation. The husband has no property or assets in his own name and no significant liabilities. He earns approximately ₹50,000 per month, with prospects of future salary increases, and owns an SUV. He is the only child of his parents and resides in a family bungalow valued at approximately ₹2 crore. No legal proceedings have been initiated by either party so far. The wife now intends to file a maintenance case. If the husband wishes to resolve the matter through a mutual settlement, what would be a reasonable and legally justifiable one-time lump-sum settlement amount, considering the wife's unemployment, lack of residence, contribution of ₹5 lakh towards the ancestral house, absence of maintenance during the separation period, and the husband's earning capacity?