Good looking 4.4 for sale, Tennesee
 

This looks like a great deal. Good mods, maintenance, and price!

2000Silver 4.4 X5, 142k Miles, Modded $7300.00obo - Bimmerforums - The Ultimate BMW Forum

No affiliation.

I could read there:

1. Occasional transmission shudder ..........

This transmission will not last long. Mine with exactly the same symptoms did it for 20k (km) and died very fast then.

BMW original refurbished transmission (part only EUR 3.500.-; with replacemant work EUR 4.242,- which is USD 5.650,-).
Add that to the price and it looks different.

Good luck

Edit: fixed my wrong prize

Would be a great candidate for a 6 speed swap :)

I think the re-furb trans can run as low as $2500 USD. I personally have a receipt for $4k on mine.

Or just take a chance on a used trans....

Add the S62 engine as well - the S62s aren't that expensive either - saw complete engines in US on m5board for 4000$. Mechanically that wouldn't be more difficult, than just a normal engine installation.