10 000 AMBER = 1.46 BTC = ~400 USD (today, BTC is high)
Don't gamble and drink less 1...2 months.

100% invested money back from dividends takes 1.5 years today (at present or slightly reduced dividend rate) = ~66% year (+there are AmberCoins with rising value)
Correct me if something wrong.
By book you have balanced investment portfolio, for example, if you invest 1/3 to real-estate/land, 1/3 to SP500 and 1/3 to AmberCoin.
Let's see.

You are not quite correct.....
At the current rate of $72/quarter per 10,000 coins, that's a return of $288/year on a $400 investment which is a 72% annual return on investment (not 66%)!
However, the profits of Amber-Trade are constantly increasing, so in reality the return will be a lot higher than 72%.
Keep in mind that the dev said if profits for 2015 are double what they were for 2014, it would be considered a successful year, "though that is not the minimum" and he also said he expects each quarter's profits to be higher than the previous quarter.
One other thing, Ambercoin is also the best hedge against bitcoins volatility because if btc goes up, your Ambercoins are worth more, but if it goes down, your dividends will remain the same!