I invested $4000 USD with very little knowledge of the bitcoin economy back in November when things were much better than they were now for miners. I ended up losing roughly $1000 USD of that original investment and I was lucky to salvage my losses to only that much.

Difficulty is now 300% higher than it was back then. TH/s machines should be arriving any day now which will make it even harder.

Don't invest money in bitcoin hardware unless you are doing it for fun and could care less if you make back your original investment.

As for bitcoin investment itself, this is pure speculation but it is my opinion that we will be range bound between 800USD and 1200USD for some time now. The risk/reward curve is therefore unbalanced so buyer beware.