my feeling baed on your info is that you';d be ripped off if you had any work done there.
If the catal conv actually needs replacement, I'd have that verified by another mechanic. You could have other issues like cracked vacuum hoses...and a myriad of other things ahead of the converter that might need a replacement after 150k miles.
That being said, replacement will run about $600 on this vehicle. I would not get it done at the dealer but have a n independent mechanic who would use OEM parts, though.
I have no idea of the extent of what was listed...as you have not shown what was diagnosed in it's entirety. However, about $500-$700 for other muffler and exhaust parts could be a reasonable guess. However $3300 is way over what is customary and reasonable. As an example, I had a '98 Honda CR-V and $500 is what it cost for replacement of my cat. converter 2 yrs ago.
However, as far as the long term keeping, rust often gets these cars somewhere around 150k-200k...unless you live in AZ or dry climate.