I had my surgery at House in November of 2005. I was not required to pay $3,000 upfront. If the providers are participants in your PPO, you only pay the percentage that your insurance states (in my case 20%) of the allowed amount for the particular care or procedure, not 20% of what you are actually charged. That is, the charge, minus adjustments to agree with the allowed amount. For example, one of my surgeons charged $18,000 for his services. My insurance deemed that the appropriate charge was $6,000. The insurance paid 80% or $4,800. My 20% responsibility would be $1,200 but I had already accumulated $650 of my out of pocket expenses (which in my case is $1,000). So I only had to pay $350 and my insurance then additionally paid the balance of of $850 of the $1,200. After that point, my insurance paid 100% of the adjusted charges and I owed nothing. By being participant providers the doctors agree to accept the allowed amount only.
Your experience might be different, depending on the agreed percentage of allowed amounts that your insurance will pay and your maximum out of pocket.