Okay I'm on my phone and not gonna type a novel but
The guy who put the v10 in an e46 already found out that the s65 6 speed will bolt right up to the s85. For the guys saying this wont fit; have you looked at a s65 versus s85 they're essentially the same and yes there is enough room to fit in the e9x chassis.
To the OP my figures from eBay are accurate and the engines found are from running cars under 40k. Most places will warranty for 30 days if you can't hear it run firsthand. And it's not my job to post the links, do a search there are used engines avail. I'm just trying to give potential buyers and yourself a reference as you are trying to sell something, no? This isn't a bidding forum. You should list a price. Good luck. Sounds like a very big project of your already doubting others info!