Hi and welcome........
I did a quick search and found the car that you are looking at............ It looks pretty clean and tidy to me.
Do you plan to drive it as a daily or a weekend fun car? Regardless, $5k should put you in a good position, especially if all the major stuff has been done.
When I bought my car I replaced all consumables (belts, hoses, fluids, plugs, seals, leads ets etc) plus had a dyno tune and the total bill was around $2200.00.
That said, if you have any major issues then the rest of your $5k won't take long to disappear. I noticed that your car has pods but the seller is offering the original air box with the sale.
Make sure you take that as here is NSW the police are rather strict on the intakes and defect plenty of cars for this reason. Personally I'd sacrifice some performance but be comforted by knowing your not going to be hassles by the boys in blue.
Other guys on here are a lot better equipped to advise on the pitfalls of the R32 GTR but after 17 years most obvious issues would have been sorted by now.
Good luck with it............
Bob.