Novant costs wildly inconsistent -- I'm pissed

Today I went in for an abdominal ultrasound that I was scheduled for via my PCP.

When I checked in they asked me to prepay $569.

I thought this was wildly out of step with what I imagined would be something more like $120, with insurance. So I checked the average in my area: cash average was $260 without insurance.

So then I dug more. Novant has an estimator tool for costs. I went through locations offering the same services in my 30mi radius in central NC. Screenshots attached.

190 - 621 out of pocket costs was the range. That is wild. Paying 300% more at one location to another in a small area, from the same system.

At this point this is probably just me shouting into the void. But God damn this should be illegal.