Basic maintenance
can cost thousands if you have to take the car to a dealership or reputable shop to have work done. A few examples; torn CV shaft boot, water pump, or coolant tank replacement can easily cost near $1,000 to have done and they are all very common maintenance items on a car this age. If you can do the work yourself, those jobs can each cost $200 or less to do. Do you have basic mechanical skills, a place to work, and tools?
Generally the statement that it is just like any other 20 year old car can apply. BUT consider that it is a Sports Car and a German Engineered car.
In a 986 thread on another forum a guy said he broke a mirror while working on his car.
Reply: "Oh no! Broken mirror is how many years of bad luck? Is there a Porsche multiplier?"
Reply: "There is ALWAYS a Porsche multiplier."
Best luck to you whatever you decide, buy well.