RE:Not SureYou can always write down on a piece of paper where you would "in theory" buy and sell at to see how well you can manage the stresses of investing and play out scenarios where you do a partial buy and then leave money aside to average down in the event the opportunity presents itself.
If you plan out ahead of time you can set up your budget into "Blocks of Cash" each one only going in if it can be done so at a lower price than your running average and then the "Cash Blocks" only being withdrawn at higher prices with the profit being left in as "Cash-Free Shares" thereby keeping your average cost per share the lowest it can be or, ultimately, having all your shares with no money on them.
I guess the other thing you could do is to "borrow" someone else's shares for awhile and then replace them later with shares you actually purchase off the open-market. The only draw-back to that is if the SP goes up and those replacement shares cost you more than the ones you got lent.