cost 1200 Euro per person!!!??

Are they so worth to listen to their stffs' full of errorrous theories & applications???

What you mean by "errorrous theories & applications"

It depends on what you want out of it! If you want pure academic stuff and hypothetical theories then you are better served by attending a conference. However, if you are into a particular field and you really want to know the industrially relevant(!) stuff with lots of cutting-edge techno info and the opportunity to talk to the guys one-to-one, then attending the VKI Lecture Series is mandatory. Lecturers are invited based on their world-class reputation in reckognition of their contribution to the subject and you can tell the difference!!

I attended one recently and in my opinion it is worth every penny. You may compare it to attending a GRAMY or OSCAR laudatio for engineers.

My other half attended one a couple of years ago and said the experience was essential. She had nothing but praise for it!

If you have a particular LS in mind, I would be able to elebrate further. I had the fortunate to attend some of the standard LS such as "Intro to Measurement Techniques", "Intro to CFD", "Supersonic Aerodynamics", "Advanced PIV", etc., and I would strongly recommend every one of those. The fact that many of the VKI LS notes are referenced over and over again as classical references tell you something.

No, they aren't worth of any penny. Stuffs of VKI are biased, too subjective minded people and suchs can not produce objective science.

Why worth so much money that far outweight the necessary expediture? Is the organizer managing an earning market ?

I attend some of the VKI LS, I never paid the full price, but what do you mean by "stuffs of VKI"? most of the LS' lecturers are not from VKI. Your affirmations are a bit too vague to be beneficial, there is maybe something good to learn from your experience. Thanks

If the issue is cost and cost only, I don't think it is any more expensive relative to an AIAA short course, or a short course on how to use .... say, Matlab, or a CFD package, or other specialized short courses I see offered by measurement technique companies.

By "biased", if you mean not covering all possible perspectives in a particular field, then I suppose each conference you go to will be "biased", and each paper you pick up will be "biased", and each book you pick up will be "biased".