Diesel is about 10% dearer than low octane (91) petrol (gasoline) here in Oz, but about the same as 98 octane.
The driveability and economy of these new turbo charged, common rail, direct injections diesels is phenomenal.
The other side of the coin is that servicing is cheaper, basically oil and filters, and that the engines still seem to last much longer than petrol (gasoline) engines.
Us far as the sulphur content is concerned, it was reportedly BMW that blackmailed our federal government into legislating for much lower sulphur content, threatening legal action if they didn't. It worked and so we now have all these wonderful new engines from which to choose !
The best thing about them, IMHO, is that they produce so much torque and many are now auto as the torque curves seen with diesel engines seem to be best mated to an auto box. All I can say is that it works !
My ML270 CDI gives me V8 - like torque out of an economical 5 cylinder.
The BMW 6 cylinder diesel engines have a similar exhaust note to the petrol (gasoline) sixes.