5 advantages of custom software development
blog.psibertech.sg
blog.psibertech.sg
If you do not find a software that addresses your needs, than it is a different story. Even than, custom developed part should be kept at minimum at possible by using ready commercial and free open source components.
You most probably won't be able to integrate it with any of your systems except maybe for big, very expensive ones that happen to be popular.
> Not to mention it would have been tested better.
Except when it wouldn't. I've seen such cases, and they are not that rare when it comes to systems that are not general purpose.
To all this add the fact that by buying a system you totally loose the control over bugs in it. You may be hit by a subtle bug that is a show-stopper for you and the producer may refuse to fix it, claiming it to be low-impact.