Why is the i7 6700k alot more expensive than retail price?

Skylake has had supply issues which may account for why there's not much availability. It may also explain the higher prices, typical supply/demand. When demand is high and supply is not prices tend to rise. Many people have been upgrading to skylake and may be buying up what's available.
 
Intel seems to be having problems with their yields and aren't producing enough 6700k CPUs to meet demand. As such, the chips have been rather hard to come by at retail, especially considering the big system builder OEMs like Dell, HP, etc. got top priority for them. Hopefully by mid 2016 the supply issues will have been sorted out, or at least the demand will have dropped by then.