Long time between oil and fuel filter change - A4 Jetta

So a cousin of mine is selling his 02 jetta. He was asking me about some things to do before selling it and what not. One thing he noted was that he hadn't changed the oil, oil filter, fuel filter, nor done much of anything since november of 2014. He said he's put about 18,000 miles on it since then and was wondering if there was anything he should check. He said there's no problems with it, other than he just checked the oil and it's really really low. He said no smoke, no leaks, no nothing. I chastised him a bit for letting it go that long, but the car seems to drive fine and no problems. I test drove it and I will say that when you step on it in 3rd or 4th there seems to be low turbo in the high rpm range, but lower range you can hear it, boost seems fine in low range.

anyway, i'm considering buying it (it's another platinum grey!) but i'd like to know if there's anything really important to check to make the low oil and long time between hasn't hurt anything. Anyone got some ideas/advice?

Long time between oil and fuel filter change - A4 Jetta