We've got a 2007 3.0si with a manual transmission. I do like white cars
Build looks good, but make sure you are comfortable with the sport package. I wouldn't order a sport package on an X3, as I find the ride too harsh. An X3 without sport package is firmer riding than an X5 with sport IMO. The ride did improve a lot over the years, and the 2007 is way ahead of earlier models, but just make sure you are comfortable with it.
Don't sweat if it has nav or not, it isn't worth paying for.
I checked stock in Canada just to see how many 2007 X3 3.0si vehicles are out there, CPO, on dealer lots. I found 162, only one of which is a manual. Incidentally, that vehicle (black, no premium, no sport, no Xenon, leatherette, 47,000 miles) is listed at $31,700. Consider yourself lucky.
You may want to do the CDV clutch delay valve delete on the X3 after you get it. It wasn't as pronounced a difference as with earlier BMW vehicles, but I noticed a positive difference driving it with the modified CDV.
Good luck with it.