An average Salary of a CCNP network engineer with 3-4 years experience is about £40-45k
If you get your CCIE you're instantly looking at 60k+. I'd say with 5 years xp and a CCIE you're likely to be on over £80k. That's what a good bunch of my friends are on with this qualification.
You don't usually have to deal with the clueless end users, the first line support or second line support deal with it. You get only the good stuff/questions to troubleshoot and fix.
You will often be involved in projects, regardless of company. So you will have to deploy new hardware and make it all work.
It's massively rewarding to fix problems that only you can fix because of your skill set.