Special TDI oil is expensive compared to gas engine oil, 7 to 8 bucks a quart and more at the dealer.
Fuel filters are 25 to 30 bucks and more at the dealer; must be changed every 20K miles.
Diesel fuel for the past several years has been more and sometimes considerably more expensive than gasoline, only recently became more equal and that will change again.
Turbo life statement is from watching TDIClub.com and VWVortex.com as is coking up statement.