Reliable... yes, it's a german VW.
Just maintain it and do keep little stuff up. 250,000 miles on the tranny, then rebuild ($900 to $1700). Major overhaul (top and bottom end) every 100,000 miles = $2500 to $3000. Top end (heads) rebuild, every 50,000 miles ($300 to $750). If it is a really fast motor, reduce the mileage by 20% and increase the cost by 30 tp 40%.