Realistically inflation will be at 4%-6%.. unless something really goes wrong.. if inflation hits, your assets will also compound faster as that will be an outcome of inflation. I am 48, didn't do much saving (market based), but doing some now. What i have noticed is that inflation is stable for a few years and then does this mad jump.. then doesnt retrace, settles down there for some time and then after 3-5 years does another jump.
I look at it like this.. if your expense is 2 lakhs.. lets say you have reached 3 lakhs per month after taxes, then you are ready to retire provided you want only this 2 lakhs wali life style. The idea is that you spend 2 and invest the other 1 lakh.. thereby saving you from future problems.. and after 10-15 years you will probably not be able to save... so even at 6-7% return.. you need like 7 crores to generate around 3 lakhs per month (split between 2 people). +another 3 crores in assets that will appreciate over time. As you age, your need for money also comes down.. so even with inflation, it wont hurt as much. My POV