Three months ago I purchased a certified pre-owned 2002 325ci with 19,800 miles on it.
I also opted for the BMW factory Full Maintenance Warranty Extension for $1200. This is exactly what it sounds like: all fluids, brakes, and standard maintenance is included plus the warranty items. So when the brakes are up, that expensive maintenance is covered 100%. Also, this warranty is recognized at any BMW dealership.
What you've described sounds like an aftermarket warranty which may have many conditions, limitations and may very well not cover full maintenance. I don't have enough knowlege of BMW failure rates to see if its cost effective. It seems expensive.
I would head over to the dealership and go for the BMW of North America warranty described above. It cost more than mine, but sounds like a better deal.