<prompt> Human: Throwaway account. So long story short, due to crypto currency investments bought btc in 2013 sold in december 2017 I have a significant amount of cash presently nearly 7 figures worth. I have a son who is presently 1.5 years old. I have a 529 plan for him at vanguard the aggressive plan which currently has around 10,000 in it. I would like to make a one time payment into it to cover his college expenses by the time he turns 18. More for the psychological aspect of checking it off of the to do list than anything else I realize that I could put 300 in per month. Any ideas on how much money I should put into it so that in 16.5 years when he is ready to leave for college it should be totally paid off for him? I was thinking another 50k or so? But cant tell if that is too little or too much. Any help or links to resources would be appreciated. Thank you in advance for any help.  <response>: Which State? Does your state have a pre-paid collegel plan? 