Here are few suggestions I can think of to make this a little easier.
1. For those who can't get a physical within a timely matter due to insurance reasosns: Schedule an appointment with your child's pediatrician or doctor. Give a medical reason for the visit ( sniffles, sore knee, etc. something minor will do) while the Dr. is seeing your child, give him or her the physical form. I've done this on several occasions with my son's pediatrician and never had a problem. It helps to have a friendly relationship with your child's provider first.
2. If, as other posters have stated, the local minute clinics can do a physical for $50 ( sometimes 30 with a coupon) , why not schedule an official troop outing to the minute clinic? Let the clinic know way in advance. Then the scouts who need a physical only need to have a parent present and the 30-50 bucks for the physical. Perhaps the scout could use his personal scout account to help pay for the physical.
3.Lastly, is there a scout- friendly Dr. or physician assistant that might be interested in setting up a quickie clinic at your meeting place? Some of the parents may know someone that might be willing to do this. A bit of a long shot, I know.