Yes, it is much better and cheaper to build the cable on your own.
My post was not targetted at offering a solution but to ask about the difference in features/price. So any clue, anyone?
The difference is the signal. SCART is for 50Hz PAL-TV. Not NTSC 60Hz. The SCART-TV got the circuitry to accept independent r-g-b with single sync line.
When doing Composite or Component Video, your adapter has to deal with correct conversion and proper signalling as all is mixed into one signal. Cvideo is a simple interface and picky to incorrect synchronization. Sync signal has to be improvised. Picture will be blurry in most cases, as the signal get "damped".
Component video carries sync signal via color. You have to make sure, signal is not getting lost during refresh.
As this was "kjmann", who has no creditibillity to me, anouncing this on a.org, lemonamiga, atariage in august and september, without pictures of the "finished and ready to ship" product, i doubt there is anything worth talking about.
Edit: From the few infos on this topic, he bought himself a tv with pal interface. So this is completely useless for north-americans and/or users with NTSC only.