The work hes suggesting is about an hour tops, dropping the oil and changing the filter should take any more than about 20mins for a seasoned mechanic with all the kit, with the rest of the time given to looking over the car.
The parts would cost, from my local factors, and assuming top spec oil, about £80quid. So that leaves £310 in labour, for an hours work. Which is, in my personal opinion, a rip off.
Ok. I have just done this job myself, I am a seasoned professional engineer and no fool when it comes to wielding a spanner.
It took me over 3 hours to change the oil.
15 Minutes were running the engine to apply the flush, then had to unbolt the plastic undertray which took a good half hour or more due to rusty bolts and tight rusted clips. After 45 minutes the sump bolt was ready to be removed, by the time I had a container positioned and the sump bolt out an hour had elapsed.
It took another 10 to 15 minutes for all the oil to drain, including waiting till the flow was low to allow the oil filter to be taken off, which too gargantuan effort using a pro chain wrench to loosen it, at which point it poured red hot oil over my gloves and took very careful handling to remove without further spillage and injury. The oil has to be drained hot so it all comes out.
After oiling the seal, and refitting the oil filter, I filled the engine with full synth, 4.5L from empty, it won't all go in at once so takes about 10 mins, thats us up to about 2 hours so far.
Then checked the sump bolt torque, the oil filter tension and started the engine to check for leaks. I ran it for 10 minutes back up to operating temp to make sure there were no problems. No leaks, checked the sump bolt and filter tightness hot once more then proceeded to refit the ****** engine under cover, which took another 45 minutes as its the most awkward thing ever invented but can't be left off or put back wrong or it will come off and allow air to rip off the entire floorpan cover (that the B5 doesnt have btw) and cause loads of grief, so I spent another 3/4 of an hour getting this right.
In short it was the most awkward, pain in the **** oilchange I have ever done in my 27 years of driving.
Tell me now thats only worth a few quid!