The final value can be the sale price, the appraised value, or the cumulative net profits generated plus the residual value of the business. Choose whichever metric best represents the total value created by your investment.

Use annualized ROI rather than total ROI so you can compare opportunities with different time horizons on equal footing. Also consider risk-adjusted returns, since a lower ROI with less risk may be preferable.

A 100% total return over 5 years translates to roughly 15% annualized, which is strong by most standards. However, the attractiveness depends on the risk involved, the opportunity cost of capital, and what comparable investments would have yielded.