The 2000 Buick Park Avenue is available as a 4-door, 5-seat sedan. Starting at $31,965, the 2000 Buick Park Avenue Base is powered by a 3.8L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 30-mpg on the highway. The top of the line 2000BuickPark AvenueUltra , priced at $ 37,160 , is powered by a 3.8L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 27-mpg on the highway.