My neighbor is on the comcast/xfinity mobile plan, I thought his was cheaper than that though. What kind of data are you looking at? unlimited? Do you know how much data you use in a month? $120/month seems a bit excessive even if you're paying for the latest phone.
I'm cheap when it comes to phones, I own all my phones and then get service through
https://www.redpocket.com/ or straight talk because they allow me to pick the provider I want. Most my phones are GSM so I wind up with an AT&T sim but they offer a Verizon sim also. I tried Ting at one point and they were through T-mobile but coverage sucked so I moved to somewhere I could get a AT&T sim. My kids are on a 2 or 3G data plan with unlimited talk/text for under $20 a line, I have a 5G plan through straight talk for about $35.