"but i would like to hear about performance parts that are within the budget of a humen."
Heh, many would say that an $80,000 M5 is not within the budget of a human. Its certainly not in my range right now. Its all relative I guess.
There are many other mods available for the M5. If you want an immediate and noticeable increase in acceleration, I would go for the differential. Also since you already have the intake and exhaust, how about a software upgrade? I think Kelleners does that as well.
Superchargers for this car require a great deal of custom fabrication and software tuning. Its not as simple as bolting a vortech onto a mustang. Black M5's car has taken a long to time to complete and it still isnt done. It would go for the mods I listed above and take it from there.
Andrew