If you're confident in the use-case of bitcoin, it really matters little when individual exchanges happen.
Do that, and if you're feeling more advanced implement an Optimal Growth Strategy based on the Kelly Criterion. If you're not a die-hard, never-sell hodler, of course.
As someone who can't afford a ton of Bitcoin I am hesitant to do this because of the miner fees. Having to pay miners fees from the exchange to my wallet and then back to the exchange can be a decent percentage of profits when you have to do this multiple times.
There is no real need to DCA, especially with concerns re: high tx fees.
Just wait to see a slight fall in price - not long, not wait for a big crash, just a little dip from the absolute top prices - then buy, and wait a few years. Guaranteed gain unless you bought at the peak of a +300-1000%-price-appreciation-in-~2-months-bubble.