My advice is try and come up with a plan of what you would do differently, status quo is not really compelling to most businesses.. Try and find a new angle, new approach (cost savings, capability improvement, speed to delivery improvements etc) as this gives you the opportunity to impress. If you want a job and are trying to create something better (pay and responsibility) then tell them what you bring and show you have thought about it. If it's compelling enough and impressive enough the wages you want can be more under your control.
The "I found out this bloke earns more and I'm annoyed" isn't really going to get you anywhere (not that you are doing that) but a "I've been in the role 5 months and here are the 3 things I think we can do better and this is how" is better.
The "I found out this bloke earns more and I'm annoyed" isn't really going to get you anywhere (not that you are doing that) but a "I've been in the role 5 months and here are the 3 things I think we can do better and this is how" is better.