A few thoughts:
1. Any time you cheap out on a safety-critical part for your car, you're risking not only your life but the lives of everyone around you. The latter is the real problem, IMO -- do what you want with your own life, but leave others out of it.
2. I generally dislike the idea that "you get what you pay for;" sometimes there are bargains, and sometimes there are rip-offs. In my experience, tires seem to be the one product for which the saying works and there are no exceptions. Every time I have bought expensive tires, I have been very happy with them. Every time I have bought cheaper tires, I have regretted it for one reason or another.
3. The usual counterpoint is "but I'm not racing so I don't need expensive tires." Unfortuately, you still have to be able to stop or swerve in an emergency, maintain control on a wet highway, trust that your tires won't lose air or blow out, and so on. Also, the poor ride quality, high tread noise, and poor directional stability of bad tires can make your car very tiring to drive.