Judging from the pics - I'd say that for 60 bucks, you got yourself a pretty decent deal.
GRATES:
The small bit of rust on them should pretty much be a non-factor. Check some of the information on Cast Iron Cookware for "seasoning" tips - that should take care of the few small, rusty spots / keep 'em from growing.
In order to avoid chipping the porcelain further - get a brass-bristly brush, and use it to clean the grates after pre-heating.
You don't want tiny "glass chips" in your food - if the rust progresses to an unmanageable level, (when rust starts to "bubble-up" the porcelain finish) then it's time to replace the grates
BURNERS:
They a bit corroded, but still solid. If they work, I would keep using them until they give-out, then replace them with genuine Weber parts.
(which will fix you up for another 5-10 years.)
Make sure that you clean-out the "spider screens" at the venturi-end (where the gas valve "jet" enters the burner) - this is where the gas & air are mixed for efficient burner operation. If they plug-up, the burners will not work properly.
FLAVORIZER BARS:
They look a bit rusty, but for what they do, that will not matter. until you start getting rusted-thru holes, which will be evidenced by flare-ups, I would keep using them. When the "time comes", I would get a set of the heavy stainless ones that people have been ordering from "rcplanebuyer" on E-bay.
Meanwhile, get some good stuff to eat, toss it on, and don't worry - you've got a real nice grill! (That unit was about 4-500 bucks when new!)