Point #3 is wrong.
Point #3 is wrong.
PS: Now if this is for 401k accounts or something that's another story.
Granted, IRA/401k etc exist and in years with 0-3% it's not that big a deal, but over 20 years it's often a significant cost.
Only if you never withdraw them.
http://avondaleam.com/sp-500-dividend-vs-10-year-treasury-yi...
I'm not sure why you are being downvoted, as the dividend component of the S&P 500 is a substantial component of the total return.
If your choices are go on a 'cruse' today, or invest your money wait 15 years and then pay for a cruse waiting seems pointless. If you wait 15 years and can't pay for a cruse your clearly worse off. If you wait 15 years and can pay for a cruse and have money left over then that's an advantage to investing.
Sure, you can consider several investment strategy's. But, you can't see the future when your deciding what to do today. So, you can't say ahead of time what the best strategy is.
And if you'd just put the money in a mattress you're down 10%, far more than the loss of paying taxes on 10%.