Most of todays disc rotors are made for light weight and cost savings therefore are not really worth turning , and honestly I've never had good luck with machining anyways....they usually end up warping again with in a year. Guess it's ok for a car that is for quick resale, but not really for some-one who uses a car seasonally or for spirited driving. My car had it's original discs replaced about 10 years ago, and I did about 30000 km's with them before they developed a slight wobble when slowing from high speeds due to pitting (rusted from lack of use) When I took her out of storage this spring the vibration got a lot worse from sitting for two years, and while I debated giving them a slight cut on the machine at work, finally decided to just fork the 50$ each or so they cost me from Woody.
Personally I think it's your best option, in the long run.(especially when you figure you have to dismount them anyways and most shops charge about the same as one disc costs to machine them .........
Ron.
