I went to the centers back in 2006/2007. All of my information on the centers is from that time period.
They do not take insurance, except for bloodwork. You can file a claim with your insurance company after treatment for the doctor's visit, however.
At the time I went, they did not require you to enter a contract with them to get treatment. They do now, requiring you to pre-pay for an entire year just to get in the door. When I went, you could pay as you go, which was nice. The doctor's visits cost about $325, and the IVs were around $175-250. They put a lot of pressure on you to buy supplements; I did buy and take some of them (they could cost like $300 per month), but I never found a huge improvement from them, only a slight improvement. The most effective and probably only treatment that I would recommend are the IVs and pharmaceuticals (anti-virals, antibiotics, heparin therapy). You can buy and take supplements on your own.
At the time that I went, Quest Diagnostics was the company doing their blood work, so it was covered by insurance for me. However, for those who didn't have insurance, I believe that I heard that the bloodwork costs somewhere around $1500.
Now, to get in the door, I think that their cheapest plan is $2000 per year. That covers 4 doctor's visits and supplements, but not IVs, I think.
As I said earlier, this is all based on memory, and most of the information is from several years ago.
Did you look up Dr. Lerner, as I suggested?