Jeff,

Rotors are an easy job, even for a novice, if they have some basic tools
and know how.  But, I would pass on the eBay bargains, unless you get a
brand name item (see below) and know what you're buying.

Instead, there are many online parts houses that sell perfectly good,
top quality brake rotors at a serious discount from BMW's parts counter
prices, and when you get right down to it, they (can be) just as good.
After all, BMW does not actually manufacture ANY brake rotors.  They
just spec them for other companies to make (Balo, Brembo, ATE, etc...)
If you buy those brands you will be getting essentially the same thing
but with no BMW mark-up.

Tell us where you are and we can recommend some good parts places
online, and the shipping will probably be less than the cost of driving
to pick them up.

Hi

Ok, firstly pass on the ebay job period...brand name or not. There are
some things you scrimp on but these are your last line of defense once
in motion, you really want to trust that to some ebay seller?? Do you
know how many fakes are sold as brand name ones? They are not a bank
breaker and last for ages so get ones you can trust. These things need
to have no play in their makeup or u will get vibrations whenever
braking.

Buy a good brand name from a good parts company, I know that the ATE
ones I got for my front where like 50% cheaper than a dealership still.
There were even cheaper ones but I wouldn't risk it.

Fitting:
I didn't fit mine but, I've got an auto mechanic who works at a
dealership and moonlights on his freetime and does all my work, he did
mine and they were quite straigh forward. You can certainly do them if
you know what you're doing, the only downer to DIY is to get them
straight and level and to not warp them by hardbraking for the first
weeks. Get it wrong or warp them and you will probably end up with a
steering wheel shudder upon braking.

PS: The dealership quoted me a stupid price just to change rotors and
pads... ok rotors and parts are not 10bucks, but still at nearly 150GBP
for an hour thats like $300 per hour, plus taxes for labour,....I
couldn't complain when my guy did the job for 40 plus me buying the
parts myself, you'd have to consider using a good independent
instead....

cheers