How much this 2009 Xdrive35D should cost

I find one 2009 Xdrive35D at about 45K miles

it has only cold weather package, in general it's a base model.
it's from dealer but not a BMW dealer, it's not CPO either

condition is above average but not very very clean, still some slight tear and wear can be seen.

is $35000 a fair price or 31000?

thanks!