To end it all, I'll just say that it's your money and if you want to use it to buy subs and destroy them, that's your business.
However, you don't have to destroy something to "push it to it's limits". I know competitors who have set multiple records with the same equipment for several years simply because they have the good common sense not to play volume master and blow their **** up.
I've probably built and tested more enclosures in the past six months than you have in your whole 10 years of car audio experience......and strangely enough, i did it without breaking anything.
PS: If you're hitting high 150's, i'll eat my f***ing SE with ketchup.