Check out the
Genesis Block Mining Calculator. You can select different mining products, and their calculator will do the rest. Now, take a look at KnCminer... which appears to be the market leader at the moment. Select "
Mercury" under their product list. Assuming you received the miner today, you could mine ~5.67 BTC. You would be mining zero BTC by next july. Your cumulative BTCs would be under 10. At today's market, that's about $2K. You've just paid for your equipment but will be no longer mining BTC.
Or, take that same $2K and sign up with a reputable exchange. Throw your money in that exchange, and wait for a market lull, then buy your BTCs. Sell them when the market peaks. Rinse repeat. If you're a decent investor, you could very well double your investment.
And finally, if you're intent on mining. Split your funds between purchasing BTCs and purchasing mining equipment (
or, sign up for cloud mining). Keeping in mind you won't make an ROI from the mining portion of your investment. If you go the equipment route, hook it up, power it up, and point it at a pool, with a minimum payout set, so that you'll automatically receive satoshis every so often. let it crank along, while continuing to play the market with your BTC investment.
That said, I opted for the latter route... purchasing BTCs and dabbling in mining. For example, when I purchased my asic miner, it was already obsolete. That is, the big boys were already out the gate. Nonetheless, I still get a little bit from my mining, and it also gives me the opportunity to play with the mining code (
i.e., cgminer, bfgminer, etc).