Without a doubt Skyjumpers will give you the most bang for your buck. There is one at Kutztown University this July. The info is at skyjumpers.com under camps.
I went to the camp the summer before my junior year and by the end of my next track season I had increased my pr by three feet (9 feet to 12 feet), and I didn't have a high school coach. I give credit to everything I learned at skyjumpers.
There are plenty of coaches, and I believe there are 7 or 8 pits run with two coaches at each pit. Plus, there is an awesome gymnastics area with a bunch pole vault specific equipment. Jan Johnson (who runs the camp) shows the campers tons of awesome video during film review sessions.
Bottom line: If you want to improve, network with a lot of coaches and athletes, have access to top notch coaches and equipment, learn valuable skills, learn more about the vault world than you ever knew and have an awesome time YOU NEED TO GO TO SKYJUMPERS.
Oh and I guess it helps that Jan's daughter Chelsea who is coached by Jan is a 15'6 jumper.