So, I understand you have a little more than $ 8k

In my country i have cheap electricity about 0.08$. This is the maximum rate
If I had 8100, I built a 3 rigs (with 5 R9 390)
Each somewhere 150 Mh/s (ethereum) + 3000-4000 Mh/s Decred (with dual miner)
It`s near 25-27$ for each per day
Payback about 120-150 days (I dont know how cost electricy in your country)

But, if it not possible. I`ll invest in these coin:

• Ethereum (now PoW, but but if happen PoS - really good for you)
• Lisk (PoS, interesting smart contracts with JavaScript language)
• DAO (With each new round of investment do not show them to be as much for the money, they are doomed to growth)
• DASH (slowly but steadily growing coin)
• Storjcoin X and Sia (rather innovative approach with HDD and cloudstorage, but Storjcoin X more interesting and in my opinion, is actively developing)