Perhaps instead of saying that a single grade skip is worthless, it might be better to say that a single grade skip is only the first step in addressing your child's needs. It is very likely that your son will need another grade skip down the line, but you can't get a second skip without having a first.
You might look into scholarships/financial aid for the private schools around you. We had to tighten our belts when we sent our daughter to a private school, but I can't imagine what elementary school would have been like anywhere else. Unfortunately, as wonderful as the the private school was, it only went through 5th grade. However a good foundation is in place and helped set our daughter up for a second grade skip.
Push for the first grade skip now, and start planning when you might want the next round of acceleration (whole, or subject) to occur. Having a highly gifted child means you will always be looking to keep him challenged.
-S.F.
