There is a lot of hidden things that could be wrong with the car, & cost half that much in repairs in the first year of ownership. This is a 90k car, with 90k cost of repairs. Have the car checked out by a BMW shop, to see if there could be any problems. If the price seems to good to be true, it probably is? There are many threads showing the repair cost of those items.
Do your homework before buying the car!