Amph,
If difficulty increases at an average of 18% then on 29th October 2013 difficulty will be 81,528,172.
At difficulty 81,528,172 and BTC of $120, a Jalapeno chugging away at 5.5 Gh/s will earn $3.95 per day.
Difficulty will continue to rise. If difficulty increases at an average of 18% then:
By 18/02/2014 difficulty will be 306,452,918 and earnings $1.05 per day.
By 02/09/2014 difficulty will be 3,109,652,526 and earnings $0.10 per day.
By 23/12/2014 difficulty will be 11,688,746,014 and earnings $0.03 per day.
The unit costs $312. ($274 + $38 shipping).
You have to recover $312. The unit becomes scrap after this as it can only be used for mining. Its not a graphics card like a 7970 you can use for gaming afterwards.
Electricity costs on average $0.15 per KW hour. So a Jalapeno chugging away at 5.5 GH/s using 30w per hour, is using 0.03 Kw/h x 24 hours which will cost $0.11 per day.
So at $120 per BTC your break-even date of arrival is 29th Oct, and if it arrives after this date you will make a loss as your future earnings will not cover the initial cost of the Jalapeno. Consideration must also be given to whether electricity can be obtained free in which case you could carry on running the unit a while longer.
If you are more optimistic about difficulty levels...
If difficulty increases at 15% per two weeks at next increase then at End July difficulty will be 22,501,570.
If difficulty increases at an average of 15% then on 10th December 2013 difficulty will be 91,031,400.
If you have a Jalapeno arriving at end-July your total estimated profit would be $1,100, if you run the unit 24/7 till end 2014 year. At $120 per BTC your break-even date of arrival is 24th Dec, and if it arrives after this date you will make a loss. At $100 per BTC your break-even date of arrival is 26th Nov, and if it arrives after this date you will make a loss as your future earnings will not cover the initial cost of the Jalapeno.
No one can accurately predict difficulty levels, however past data should allow an estimate of the future.
Neither can Bitcoin levels accurately be predicted. Bitcoin has no intrinsic value other than the opportunity cost of using it relative to transaction costs of other payment mediums. This means that there is no guaranteed upside potential other than during speculative bubbles. The price of Bitcoin seems to have stabilized around USD 120 after its wild swings in the past two months, and it is quite reasonable to use $120 as an estimate of future price. However investors in mining rigs need to consider scenarios where the price drops $100 or $80.
A Jalapeno is a cheap flutter and for most people if they are only buying one or two Jalapenos it's really a fun gamble rather than a serious investment. Butterfly Labs has very cleverly pitched their price at $274 as this has allowed them to obtain tens of millions of dollars in pre-order deposits, and at this price they believe buyers are not going to make too much of a fuss even if they get their items very late.
how can he make a loss with a jalapeno, with a consumption of only 30 watt?
he eventually will catch up the difficulty and make roi, sooner or later...