You are right, that is the price I would have paid including a loaner car. The warranty company on the other hand pays reduced labor cost (75-95 dollars an Hr vs. the 125 I would pay). As well they can negotiate on parts. For example my nav screen was out of stock in my area so the warranty company ordered one from California BMW dealership and provided it to the dealership. My dealership wanted around 4K for the navi screen with their markup. The warranty company paid $3,300 for it from the one in california including shipping.
To answer your question, yes it is a savior and the only reason I still own my car. The Day it expires or before it expires I'm going to sell the car. I've saved 36 thousand dollars while owning my car on repairs.
I work on my other cars regularly and have replaced a timing belt and installed a supercharger myself so I know my way around cars. However a simple mistake on these cars can cost THOUSANDs to fix and plus most of the electronics require programming and can become bricked while programming. I rather leave that to someone else in the event something goes wrong rather than have to shell out 3-4K replacing modules that were bricked during programming. Plus I haven't had to pay for all the Logic 7 repairs and electronics that I couldn't have repaired myself.
The town that all of this happened in didn't have any sort of shoulder to pull onto, just a sidewalk and the road is 1 lane each way. The parking lot was about 300 feet away so I just pulled into it. I carefully drove my car in and had it towed 150 miles to the dealership that has 760 specialized technicians and whose familiar with my car. I've seen the same thing at BMW, MB, etc. Some folks are VERY stupid and are far from mechanically inclined. Someone I know didn't even realize that they had a blowout for 30 miles until a police officer pulled them over. People are stupid in general, the only thing we can do is educate ourself and 1. avoid them or 2. help them. I'm of the latter opinion and that's why I post my experiences here.
If you want to work on your car, go for it! The community is here to help with that, esp members like Kief! However for some who can't afford to spend 2-3 days fixing their car, this warranty is great. I can sit in my office and browse bimmerfest at my leisure while working or I can spend that free time at home doing things with my family. Others can take their loaner car and go to work like normal! Was the 10K a large investment 3 years ago, you bet it was. However it's one that paid off and I have profited from, not only in a monetary sense but as well with my family. While my car's in the shop I can continue to enjoy with my family, play catch, go to the park, etc.
As the saying goes in vegas, I'm playing with the house's money now!