If you're on private insurance or an HMO, talk to your doctor or a LC about getting insurance coverage for the pump. You may be able to file a medical claim that shows the pump is needed to treat your infection.
When my son was born at 30 weeks, he was unable to bf and I needed to pump. I got a prescription for a breast pump from my OB, and my LC submitted a form that described why the pump was a medical necessity. My friend had the same LC and when her daughter had latch problems, she also got reimbursed for her pump. It took a month to get the money back but it was worth it -- we each only paid our $10 copay on a Medela Pump In Style!