Both of those items are emissions control devices, your car does not need them to run properly, except if the Cat clogs the exhaust up.
The EGR valve runs

$401 at Parts America.com. YIKES!
Do you have an Auto-Zone or Advance, go there and they can pull the code for you, you can see for yourself. I'm sorry, when it comes to that kind of money I trust no one.
Get the Cat replaced, hold off on the EGR, it will only hurt you if you have to pass emissions testing. You can look into it later, maybe get a good used one.