Roughly half a bitcoin a week.

Discarding all the details; Today 550 GH/s brings in about 3btc or less a week.

The two big factors you are facing are:

• Mining companies (some you hear about, some you don't) coming out with 1k - 2k TH/s machines in that time frame. Then there is KnC who will be close to distribution with their 3-4k TH/s Neptunes a month or so later.
• Price. If bitcoin hits $3500 -$4000 mark by March then your investment may be worth it... better yet if you can crack half a bitcoin in three months and the price touches $10k-$15k well, therein lies the gamble.

All it really boiled down to was 'do I believe in bitcoin or do I want to make as much fiat currency as fast as possible.' Chasing fiat is like a dog chasing two rabbits with a high probability of losing both. Chasing bitcoin... well I wish I could predict what was going on at the time your mining machine would arrive, but I'll always bet on BTC.


~Jord