Two comments.
If the full meal deal maintenance cost is $10k (assuming similar terms) and you buy a breakdown policy for $3k, then that is fine, but you should expect (on average, there is that phrase again) to spend an additional $7k during the term of the policy, on non-covered items. If you want to not have wallet shock during your ownership, the higher price should be your budget, whether you self-insure or buy insurance.
Secondly, as a species we are remarkably good at making ourselves feel good about what we have chosen. We celebrate buying a policy and getting 'more' back out of it, ie beating the bank, even though we should know rationally that it doesn't happen very often and is not likely to happen to the next guy, at least if the insurance company is going to remain in business. We don't buy a policy and celebrate when we win, ie squeak through. If we buy a policy, we are unlikely to decide later that it was a bad decision, because we got peace of mind. So, as much as we like to complain about things, we will all tend to post that we made the right decision. And we can't all be right, especially when vendors are making money off of our decisions on these matters.
Enough philosophy. Good luck with your decision. There are reasons why a fully policy will be expensive for your vehicle, and why a cheaper policy will have lots of exclusions. Whichever you decide, find a good independent mechanic, because as I was taught when much younger and dealing with similar issues as a service manager, lawyers and accountants don't actually fix cars, they just bet on outcomes, and offering insurance policies is one method.