1993 LS400, just hit 205k today, everything is running fine except sometimes when I break theres this horrible knocking noise coming from somewhere underneath the car. My first guess is the control arms but I never thought they were capable of sounding this bad. any thoughts? Im not ready to dish out $700 to get new arms

It could be your caster arms. They prevent the body from moving forward relative to the suspension. Mine were shot at 80k miles and they had apparently been replaced before as well.

if you dont mind me asking how much were they to replace?

I'd have to find my receipt which means a 1/4 mile hike to my car, but even then, I get an employee discount so my cost is different. Call your dealership's service department and get a quote.

If it is only while braking - check to be sure caliper bolts are torqued properly. Mine did the same thing and it was due to the bolts not being torqued properly - caused a loud knock.....easy thing to check.