Pars,
As djbnh stated,no two revisions might be exactly alike but I will try to give a basic idea. Take it with a grain of salt as it's been a few years and my data is not current and more informed people can correct me.
If you haven't seen it,go to the members section and look up EduardoAAVM on page 71. He's the Mexican Odyssey rep and has a nice website. It's in Spanish but has usable info. Click on the globe symbol to the right of his name,that will take you to his website.
Click on the "Odyssey" box on the home page,that will give you two options,"Odyssey" and "Gronneberg". The Gronneberg option will show you the various wiring permutations.
Hover your mouse over the Odyssey link,and a drop down menu appears. Go to "Amplificadores" and select "Stratos" and a table of the various standard models will appear with differences and prices at the bottom in USD. The differences in price will give you a VERY baseline idea as to upgrade cost.
The Extremes were the second tranny added. Now,if they are using the Red single thickness Symphonic Board with upgraded parts as well,the mod has more to it now. This is the first of the "serious" mods and still probably has the most bang for buck.
Years past there was a "Extreme SE/SE+" mod that added the double thickness board(originally blue,now black I believe),more upgraded internal parts(caps,etc.) and some use of Gronneberg TS Premium(grey) wire instead of all blue Quattro Reference.
Now,that has evolved to the "Glass Ceiling" with even more upgraded internals,and more TS Premium used.
You're certainly into 4 figure cost territory here depending on where you're starting from. Look at the Kismet retail price and reasonably figure at starting around half of retail,give or take depending on what options you end up with. At this level,the mods take a lot of hand labor and Klaus said those double thickness boards require alot more effort than the single plus the added parts cost.
Now,there's any number of many,many directions Klaus can go so price can vary significantly from mod to mod. that's why it appears people are being secretive,it's just that these things vary a bit from amp to amp and no one other than The Big Guy can say with any authority what things will go for.
Sorry for the length,hope this helps.....
