This is a great thread and very informative, helped me fix my problem at £0 cost.
Some months ago I had the issue of only setting 4 worked on the blower, so I replaced the resistor pack (£12 off ebay) and that got it working again on all 4 settings.
Just recently the blower stopped working on all settings, so after taking out the blower motor and confirming it was the cause of the issue by checking it on a battery charger, I was going to replace it with a second hand one off ebay for £30.

I then discovered you can remove the motor from its housing, there are 3 rubber lugs by the screw fixings, then it just pulls out with some wiggling.
It turned out that the only thing wrong with my motor was that one of the springs that holds the brushes against the arbiter had Brocken, I actually found a similar spring in the shed I could use as a replacement, otherwise you could probably buy one for less than a pound.
The motor in now fitted again and running without any problems, so it’s worth checking that the motor is not completely dead. Note: whilst you have got it out best to oil the bearings.

My dad took his ford focus to the garage two months ago to get the same repairer done and it cost him £370 inc VAT, £255 ex VAT for a brand new blower motor.
Sometimes it really does pay to do it yourself, although it did take me most of a day to sort it out.