My question involves independent contractors in the state of: California

I am being sued for a total payment of $1,300 for which I plan to fight the best I can as I feel the suing party is at fault rather than me. After my response papers have been filed with the court, the collection agency contacted me and offered that I could agree to pay up now or otherwise the cost for me could increase to over $3,000 as there will be hefty additional costs for going to trial. Our conversation was too brief for me to find out how my costs could increase to more than what I was being sued for.

My questions:

1) I thought under the worst scenario, I'll have to pay just the $1,300. How could this get increased to over $3000 by going to trial?

2) I feel I have a good chance of winning a jury trial. Would I be able to have this just by paying the $150 jury trial fee?

3) A Case Management Conference has been scheduled. What is typically done at the Case Management Conference? Will there be a mediation, or will I be able to insist on moving to a trial?

More backgrounds of the case:

I am a Medicare recipient who had my first colonoscopy performed by a clinic in 2015 and this was duly paid for by medicare. Under the doctor's advice, I returned in 2018 to have another colonoscopy performed. At the time of registration, I was asked about my insurance and my answer was that I had both Medicare and Kaiser coverage believing this to be true. Unfortunately, it turns out that both Medicare and Kaiser declined to pay as I should have the colonoscopy done by Kaiser doctors and the cost will be paid by Kaiser. Now the clinic is suing me for violating a financial responsibility statement I signed for my first colonoscopy done. My defence will be based on 1) The financial responsibility statement was a one-time use agreement and does not apply for the second time. 2) The clinic being the professionals that they are, should know that under the circumstance, the cost of my colonoscopy is covered only if the procedure is done by Kaiser. But for me, I have no such knowledge clearly illustrated by my statement that I had both Medicare and Kaiser coverages.