I agree with Warren to keep it simple and not use higher mathematics in your analysis.
Making a decision to sell is the most difficult thing we do.
Ben was a very simple straightforward man with a brilliant quick mind.
Use book value as a starting point to try and establish the value of the enterprise.
I found that it was much better to look at the figures rather than people.
If you are honest, hardworking, reasonably intelligent and have good common sense, you can do well in the investment field as long as you are not too greedy and don't get too emotional when things go against you.