why don't you stick to your original objective and apply for a cs master or even a phd? it seems to me that what lz has is more like an "education goal" rather than a "career goal". mba is afterall a career oriented education. you'll have to spend a lot of time on socializing, networking and job hunting rather than "花多多时间在学业上啊,学到本事". in addition, no offense, lz's opinion on taking loans is basically anti-finance and anti-mba. think twice on "why mba", that'll be my suggestion.
Agree with WendyT, think twice why MBA why master/phd, those whys can help you articulate your goals and motivations in the essays. Remember, good essays are important parts for admission.
BTW, loan is not as horrible as you thought, most businesses use some financial leverage after all. consider your education an investment, if you manage it properly, you will benefit from it for the rest of your life