I have smoldering multiple myeloma, multiple sclerosis, CHF, and high BP. I went to the Mayo Clinic about 15 months ago and had tests results that answered a lot of questions for me. It didn't change any of my diagnoses but I had answers for the first time. I had from 2-5 tests every day for 5 days. Like you, I am out of network and have a PPO. I called my insurance company and they told me I could get a second opinion anywhere I chose to go. The clinic costs to me were about $1500 as near as I can figure out from my old records, many a little more. I had expected to spend maybe $5000 so this was good. My airfare, hotel, and meals were extra, of course. I shopped around for airfares and hotel costs and stayed across the street from the clinic. I am thinking about going back again as it looks like I may need to start treatment for the myeloma and would want a second opinion on this aspect.