There are many vendor makes the 78M05 at different price, what makes them different?
Other than the package material, the most critical thing is the silicon design, in other words, how many active transistors are used. 

Here is what I have found:
1. OnSemi, MC78M05BDTRKG, 28 active transistors.
2. Diodes, AS78L05RTR-E1, 24 active transistors. 0.1A, not a 78M05 device, but similiar.
3. Rohm BA78M05FP,  18 active transistors.
4. ST, L78M05ABDT-TR, 17 active transistors,
5. UTC 78D05AL, 78D05LL, 78D05L, 15 active transistors,

The following are the schematics posted on their data sheets:
1. OnSemi, MC78M05BDTRKG,contains 28 active transistors.

2. The Closest Competitor: Diodes, AS78L05RTR-E1, 24 active transistors:

4.The third closest competitor: ST L78M05ABDT-TR, 17 Transistors

5.Other competitors uses 15 or less transistors: UTC, 78D05AL, 78D05LL, 78D05L, 15 transistors,

涉及到电源, 一定要用好的零件, 电源一坏, 故障指数级增长.

还是挺喜欢楼主的这篇对比.  

是不是可以理解为成本跟晶体管数有关呢?  这就不得而知了.^_^

The number of active transistors determined the size of the silicon die, which affects the cost  heavily.

The rule of thumb is: 80% of the quality control/issues can be determined by design.

This is another comment on: how important it is for quality control:

"就单说纹波方面，TI出的比国产的2596都要低很多的，只可惜实在是太贵了。
前几天公司的一款设备上面的一个三极管坏了，当然就用户的角度来讲，就是你们的设备不好，然后大约损失了三十万吧。
前段时间用长电的7805，坏了一片，还好没发货，这个我要点名批评，发货了就又是一台几十万的设备被退货。再然后，我就不敢再买国产的芯片了。
真不是说崇洋媚外，国产的如果货期短联系厂家方便谁会不买呢。只可惜现阶段还是有点不争气啊
"

>难道发布会那天你也去了？

what are you talking about?

Visit the URL: http://t.tt

the vedio:http://v.youku.com/v_show/id_XMjc1NTQyOTU4MA==.html?spm=a2h0k.8191407.0.0&from=s1.8-1-1.2

The promote video:

http://v.youku.com/v_show/id_XMjc1NDQ5NjA0NA==.html?spm=a2h0k.8191407.0.0&from=s1.8-1-1.2

the news:

https://www.engadget.com/2014/08/11/smartisan-ceo-luo-yonghao-profile/

感谢您的帖子。

我也深受其害，AMS1117之前的在12V下工作都是正常的，这次在LC买的AMS正品呢，上去不到一分钟就完了。这一批料被搁置，只好重新换了电源方案。

原来是这个原因，不知道应该怎么区分呢，谢谢！

>原来是这个原因，不知道应该怎么区分呢，谢谢！

I think the following three factors have a lot of affects:

First, it is the silicon design;

Secondly, the silicon manufacturing process.

Thirdly, packages process for IC.

>这次在LC买的AMS正品呢，上去不到一分钟就完了。

More detail? Do you have the part number?