Your tone needs a lot of work here. First, you're asking people to help you by purchasing something they can get just about anywhere cheap - and then you get a bit of an attitude with them about it.
But, even worse perhaps (I can't decide), there is no linear thought process to your letter.
You have...
The "benefactor" wants me to pay him back as soon as possible and if I don't pay him at that day (6/6/2008, he will have to charge me 6% interest, DAILY. Can you imagine that?
Over 5 Gigabytes Worth Of Hard Disk Space!
You think I'm lying don't you? Well, I'm not. it is TRUE and it's up to you whether to believe it or not. But if you don't, you can leave this site now but if you decide to believe in me and want to help me, here are a partial (there are over 5 gigabytes of MRR, PLR products for you):
The line "can you imagine that?" leads me to contemplate what the cost would be like, and suddenly we're talking about disk space? What just happened?
And of all the possible benefits of having a mound of PLR, you chose 'losing 5 gigs of disk space' as a subhead? Yikes.
My advice is to lose the sympathy hook, don't mention the disk space, and just sell the stuff cheap and focus squarely on how much one could make with it.
And definatley lose the word "benefactor" - it's one of those words people associate with those Nigerian money scam letters.
Good luck.