"My parents nag at me": This part of the sentence suggests that your parents are continuously or repeatedly urging or bothering you about something. "Nagging" typically implies persistent and often irritating requests or complaints.

"to help them change to unifi": Here, it appears that your parents are asking for your assistance in switching to a service or product called "unifi." This could be related to changing their internet service provider, mobile plan, or something else that involves a switch to "unifi."

"because it is cheaper": This part explains the reason your parents want to make the change. They believe that switching to "unifi" will save them money, making it a cost-effective option.