I'm not an electronics expert, actually, I only know how to use a soldering iron

But iI followed the great tutorial on this page
http://ryoandr.free.fr/english.html to make my own VGA to SCART cable and it turned out REALLY well.
I didn't need to open up my TV, since the SCART connector is on the outside.
The only thing it costed me was some time researching and reading up on how to make the cable.
Lettuce, if you have a friend with some electronics/soldering skills, he'll build you the cable in 10 minutes.
Then it's up to you to adjust the software. I admit that there's a risk involved if you send your TV a signal that's completely out of spec, but I've seen some tinkering going on in these forums that were WAY more riskier than this VGA-to-SCART-RGB hack.