As long as it has been mainteained well, it really shouldn't be much trouble. Those are really low miles for a 1999 model. My E36 1996 328i (same engine as that 323i, only with larger displacement) has 197,600 miles on it, and all I have had to deal with is general wear and tear/maintenance. I would have the car inspected by a BMW mechanic (either in a shop or a dfelaership, at about $100 in either place), and would be ready with upt to $2000 (just to be safe) to replace all wear and tear items for which you are provided with no maintenance record. I am talking about all filters, hoses, belts, etc.
I say it would be a good pick.