what is the net advantage of leasing and the NPV?

The amount to buy - 3,000,000 payable in 4 years with 40% corporate tax, it has a depreciation value

Maintenance fee annually - 100,000 with salvage value of 500,000 is 25%, 1,000,000 is 50% and 2,000,000 is 25% with 8% loan rate

the machine lease is 675,000 per year and the company and probably with a tax-exempt municipality discount of 5%

What will be the Net advantage in leasing, the NPV and which is better buying or leasing? please show me the formula and the calculations and in the Microsoft excel.