HPFP is a thing of the past. Get service records and find out all details of what was fixed on the car.
Generally speaking, the 09's are fairly reliable, even more than 07/08. A lot of the parts on the '09s are on their 3rd or 4th revisions. You can look this up on realOEMparts.com.
I have a 09 myself and it has been fairly reliable. The HPFP was replaced voluntarily and I didn't have any problems with the old HPFP or the new HPFP.
2009 335i 6MT - M-Sport - All stock