1. The flavorizer bars rust out?
2. The burner rusts out?

In my experience just about all metal appliances that are used out side in high-heat situations will eventually rust. There are some steps you can take - to treat them as you would any cooking utensil and clean thoroughly after each use, spritzing the grates and other cooking surfaced with a high-temp vegetable cooking oi. And the burners and such - protecting from moisture, etc.

Of course, no one does that.

So the only alternative is to purchase grills with grates and other parts that a) are made with materials and processes to withstand neglect and abuse which always = $$$
b) are warrantied to be replaced if/when they fail which is also part of the price = $$$

lower priced products usually have either bullet-proof systems or no warranty.