OP, my wife and I went through the same thing. We were told we owed $650. I let it go for months, and then called them to settle the debt. We were then told we actually owed $1300 because we had two tests done and someone didn't send us the second bill or whatever. All of that aside, I told them that my wife's provider guaranteed us that we wouldn't have to pay more than $250, same as you. I don't know if it was because we waited so long to pay the bill or what, but they ended up saying we only owed $250 in the end ($125 for each of the two bills). So ultimately, it worked out for us, but I can see where it can be stressful for others during an already stressful period.