I hate to say it, but to make more $$$ you’re going to need to go up the ladder and out of desktop support. I finally made that jump and have almost doubled my pay. It took quite a bit of home study, my own home rack of equipment, setting up my own servers, firewalls, virtual machines, active directory and such. Find out if your company offers an MSDN subscription, get some surplus machines, and start setting up your own domain at home. Grab GNS3 to get familiar with Cisco. Learn command line Linux. Learn PowerShell.
What you do have going for you is the customer service you get from desktop support. Stress that! Many others can’t effectively bridge between the network and the end user. Too many teir II and teir III groups are shut off from the end users, make unannounced changes, and generally muck up workload due to poor communications.
Start networking with other people in other IT areas. Get to know your network admins, your system admins, the people who configure the login scripts and AD groups. You may be almost “topped out” on the desktop payscale.
As you learn in your home lab, add those keywords into your resume right at the top. I had a whole page of them.