What is your view of using margin at 6% to average down on excellant stocks like CHL if cash is not available.

Most people should not invest on margin. For those that do, it should be in the earlier stages of an overall market uptrend and not near its end. Investing on margin near the end of the overall market's uptrend increases your risks. So if CHL dropped from $50 to $35, you might get a margin call and get sold out of the position and lock in a loss. No need to take that type of risk.