Guys unfortunately it comes down to supply and demand. There are more 35/50i models out there than M models. Tuners won't spend the money on R and D if the demand isn't there. Look at the stupid hamann or AC package that someone posted a while ago. I forget the numbers but it was something like 30-50k for a few parts! That's insane and unfortunately probably the only way that company will recoupe their developments costs.
Most of the M owners aren't on these forums and don't modify the car. In many cases bought it because its the top of line.
For example, I was next to a guy at a gas station last year with the new S65 AMG. I asked the guy how he liked the design, engine, tranny, etc. opposed to the previous. The gentleman was probably in his 50-60s.
He told me he had not interest in the performance and bought it for the safety?
I said to him you do realize all the safety features are in a 550, the bluetec, etc and he did not need to spend an extra 50-100k or whatever it is for the V12.
He responds, oh well it's the most expensive as well.
My point is, unfortunately we are limited. To the poster that asked he needs to upgrade because a tune. NO.