Alright...the M5 resale market is officially so bad that you can not pretty much get a loaded M5 for the price of a loaded used 550i. Great for you! I have lowered my price to
$55,000 on my immaculately cared for M5. This is my "second child" (my wife's take on it).
Tons of pictures and details at
www.wedewer.com/m5 I'll update the pricing there as soon as I can log into my server.
Mileage: just under 25,000 at time of posting - less than 1k/mo.
Options: Black perforated merino leather, ventilated seats, M Multi-function seats, fold-down rear seats, comfort access, Heads-up display (HUD), rear sunshades, aluminum trim.
Upgrades: K&N intakes (also have stock airboxes), Dinan FRC and rear sway bar, EvoSport Pulley kit, Solaris silver bulb kit, aluminum custom pedals, Umnitza Predator ICE angel eye bulbs.
At this time, I am willing to work with someone on the inclusion or exclusion of the RAC Monolites wheels/tires. The stocks wheels/tires are on the car now, and have probably 30-40% wear left. The RAC Monolites have only 2000 miles on brand new Toyo T1R tires. If you want the RACs, or both sets of wheels/tires, make your offer accordingly. Understand that the RACs are $4500 wheels, which $1800 in almost brand new tires, so offer accordingly (for reference, I have been offering the RACs with tires for $4000 + shipping).
Car has been meticulously cared for, with Zaino products gracing this Beast since day 1 along with a few other nice car care products for various interior and exterior points.
This Beast was built in April 2006 just for me

Yes, I had a few transmission cogs early on, but nothing that left me stranded like some (Ashok) and the sensor recall and software update took care of that...haven't had one since.
Also, as a private party seller, Nevada does not charge any sales tax to buyers here. You may or may not have to pay sales tax to your state if you buy from me, but if you are a Nevada resident, a resident in another state with no sales tax, or you have a similar used-car purchase provision as Nevada, there is no sales tax from me! Save yourself a few thousand dollars compared to dealers, AND get the complete and full history on the car you're buying. Trust me, that will be valuable when you go to sell the car as a second owner too.
PM me for details, phone number, etc.