Tag manufacturing makes the 22 degree offset with the steering stem and bottom bearing included. The suggested list is $349. But with a little searching, I believe you might be able to get them for around 300.
I saw them at my dealer's in a older catalog that he had. I just check tag metals web site, and you are right, they don't list them. I did find on a website offset triple clamps that the offset is changable with different inserts.
the website is www.qualitysmart.com sorry about the misinformation.
My goal in changing the triple clamps is to get my 99 yz250 to turn as well as my son 02 yz250f. My 99 seems like it is a little longer, and I think that it will help it on the inside lines. I put a longer 03 shock on my bike, after my linkage broke snapping the shock in two. It seemed to help it turn better. Also the addition of high speed adjuster on the shock is nice to adjust the amount of squat under acceleration. I am going to ask my dealer if he can still get the tag triple clamps listed in his catalog. If you contact tag, and they still make them, please post it. I will post if he can still get them. Also he will give me a decent discount. I will post the price for you if he can get them.