When the benefit of realizing the dream is larger than the cost of cash, people will go for it. The calculator is nothing but your mind, not someting written on the paper. Even if you can figure out an exact number by using, say, discount rate, you still cannot give it up if this is really something you want.
Trade-off is not easy, since the value of your dream is not easy to say.
也许我的看法稍微市侩了一些。现实点来说,对于有top school dream的人来说,自己要有professional一技之长,可以等经济有好转迹象的时候再去读,就是说不管什么时候读,出来都会有很好的出路那种;对于只是有出国梦的人来说,就越早读越好,选择奖学金多的学校或者专业读,降低成本,然后做好心理准备放低姿态回国工作,女孩子可以不要求太高年薪,就像我的打算一样,然后在30岁之前重新定位自己的职业方向;对于把MBA当作事业追求的一部分的人来说,可以衡量一下这两三年,究竟是“浪费”在学校里回报大,还是“浪费”在事业上回报大,谨慎选择。