Fuddy, Ha, ha, ha.... I was wondering when you were going to post that part. That job is all in removal of the intake plenum and the 8 seperate runners. What they also neglect to mention is the fact that you have to break your hand in 5 places to get the purge lines off the valve. That valve is buried in a place that was never meant to be seen with the motor in the car. I always love how they casually say "remove hoses". LOL!!! I guarantee that picture of the valve is taken with the motor out of the car.
Anyway, I've been watching this discussion and figured I'd chime. Having had some experience with those valves in the past.
Better to be on the lookout. Watch what shops are up to and don't be afraid to ask questions. In this case I'd also be careful what you read on the internet.
Let me break this job for to you.... Car comes into shop. Service writer greets and signs in customer. Technician is assigned vehicle. Road tests and verifies customer complaint. Any proficient technician will then perform a charging system test before proceeding with any type of electrical system diagnosis (not often a problem, but it can run you in circles if the charging system is weak). If it's a dealer or a high end shop they will then hook up the BMW GT-1 diagnostic tool (A tool which happens to cost around $16,000 and is necessary for most programming procedures). Once the tech retrieves faults it is necessary to understand them. I'm guessing this purge fault was a 232 which states "purge valve malfunction", but doesn't point a finger at what is malfunctioning. It could be a vacuum supply problem, an electrical fault with the signal to the valve, a valve with a faulty electrical actuator or a valve with a faulty plunger. If it isn't diagnosed correctly it results in a second or third removal of the intake plenum (not good....). Whether that is at the shops or the customers cost depends on which shop it is and how honest they are. A tech armed with the GT-1 can activate the valve to make sure it's getting signal. A noid lamp or voltmeter can verify that signal if the valve is faulty electrically and not making a "clicking" noise when opening/closing. More often than not the valves will continue to open/close even though the plunger is faulty. This is where a lot of untrained techs will go wrong and assume it's OK. You must then check the plunger to make sure it's actually sealing it's orofice. If the valve proves faulty then you're good to go with the repair. If not, then the tech must report to the service writer advising that they will need further diagnostic time. Provided it's just the valve (as it usually is), the tech turns in a diagnosis to the service writer who provides a request for parts to the parts guy who calls the parts house (presumably the dealer for OEM parts). Once the price is obtained a repair estimate must be created, the customer called and the repair needs to be OK'd. Once the part is ordered and arrives the technician then has to install the part, clear faults, road test and report back to the service writer whether it is repaired or not. Oh, and in this case, because there is an update... The computer must be reprogrammed using said GT-1.
So that's it... Just a simple little repair that ends up being not so simple. The other issue is that diagnosis is impossible with the intake in place so frequently you have to go out on your own dime and remove the intake. If the customer doesn't approve the repair at that point then your stuck with the wasted time of removal and installation just for the sake of a diagnosis.
The added parts expense of buying through a shop is usually what's necessary to get yourself a proper warranty. I've never been to a shop that will warranty parts from an outside source. Even if you do source your own parts you are frequently close in terms of cost once you've paid shipping, plus you may be up to a week out on getting that part delivered. What's having your car worth to you while you wait to get that part delivered?
That's about it... Make sure you always look at the whole picture. If you look at what Jon posted above you see that it's pretty realistic, but he doesn't break out the diagnostic or the parts price for you. It's also goofy what he says... BMW is soo far off on their times sometimes. They quote 1.7 to replace the valve, but 1.8 to remove the intake. Now, unless you're Kasper the friendly ghost you can't remove that valve without removing the intake and yet they call for less labor to do the valve than to do the intake by itselft.
Being a tech myself I sometimes feel the need to reply to these things. There are a lot of honest techs out there looking to do right by you, just as there are a lot of sheisters out there. The most important thing you can do is build a relationship with an honest shop. They'll then value you as a customer and make sure to take great care of you. Look how busy a shop is and you can usually figure out how solid their customer following is.
Anyway guys.... Good night, take care. If you've got questions, feel free to e-mail me. Now that I've finally signed on here I'll be sure to post more frequently. I may even think of trading the M3 for it's big brother one of these days.