Well I must say, even though the $20/$100 looks like 20%, that $100 is a 500% return on the initial $20. Considering that the likely original idea was to simply to splurge and spend the original $20 anyway, "investing" it and getting $80 in the bank while still getting the $20 to splurge with is commendable.
There's a phrase for this kind of math... what was it again?
Oh yeah, "Lies, damn lies, and statistics."
The thing that amuses me the most about this isn't the spending 20% of their investment, though... you want to get technical, the approach cited has basically earmarked $120 out of the general spending fund, not $100, and not $80 invested. The net balance of worth in this situation may only be $80, but the suggestion is to invest $100 and then spent
another $20 on top of that.You know what's an even more awesome treat for investing? Investing the extra $20 set aside for a treat on top of the $100! Even bigger long term return, same impact on short-term monthly budget bottom line!
Isn't math fun?