Yeah they aren't so cheap, but not braking easliy. Grade nine is tough, 12.8 is aerospace approved.
I cant find the site anymore but they were located in Miami Florida yada yada airspace fasteners.
But these guys have 10.9 fasteners. I've got my throttle body hardware from them because fastenal was out of stock. They are relatively cheaper and strnger then OE by 18.5%. The 12.8's ran me about 15 a bolt times about 12 or 15
http://store.nutsandbolts.com/mehexcapscbg.html