You didn't include buying with DCA to be used by a high income earners? It is mostly advisable to use the dca as a newbie investor even as high income earner than using the lump sum or buying the dip because the DCA strategy will work you down the road of understanding the market. A high income earners can also use the DCA strategy, you need to understand that DCA strategy is not limited to only those with a little discretionary income but it can use by all levels of investors and secondly anyone can take advantage of buying the dip too provided that they planned for it.
Buying the dip is never a bad idea as long as you are not waiting for it before buying, you can be buying regularly through the dca accumulating strategy weekly or monthly, but once their is a strong dip in the market, you may decide to buy aggressively only if you have a reserve fund to do it, but if you don't have a reserve funds in place to take advantage of the dip, their is no point getting worked up or trouble about it, just continue your dca accumulating strategy and this time try to set up a reserve funds because the dip will surely come again in the future, but waiting for it before buying is a very big mistake any Bitcoin Investor will ever do to himself, because waiting for a dip before buying will make him miss a whole lot of buying opportunities that would have made him add more unit of Bitcoin to his stash if he had been buying and accumulating regardless of it price.