Another pricey "toy" in my wish-list

I asked my Beijing colleague about some photo-taking technique (he went to Tibet too in May, and I saw his photos, he has some talents!), about how to take a photo, where the focus is clear, but outside the focus area, all blur blur one. Below is what he explained to me (i scared I forgot, so post it here then I can remember, haha):

你讲的焦内清晰而焦外模糊，在摄影上被叫做景深，景深大就是指焦点和背景（焦外）都清晰，景深小就是指焦点清晰但焦外模糊。
控制景深大小有三个重要的因素：
1，光圈的大小。光圈越大，景深越小；反之光圈越小，景深越大；
2，镜头的焦段。长焦端拍出的照片景深就小；反之广角端拍出的照片景深就大；
3，相机距离拍摄对象的远近。距离拍摄对象越近，景深就越小；反之景深就大；

所以如果想拍出这种效果的照片，首先要换一个大光圈，带长焦镜头的相机。
结论是：投资买一台单反相机吧！

See how talented he is? Anyway... I am toggling on the thought of getting a more professional camera.

Ta-Da~~~~~ Panasonic Lumix DMC - LX 2. Cost around 4-5K. Wow... another big investment.

I still love my Sony Cybershot, but that babe can't do 景深. Damn.

Is it worth to spend 4-5K on a guy's thing - camera? Tell me~~~ Tell me~~~~