Waiting to buy Bitcoin at the dip is not a good decision for anyone that want to make good investment in Bitcoin because it's not certain that the price will reduce to the minimum expected value that you targeting before you will buy and this can make someone to loose a good opportunity buying Bitcoin at a good rate if you consider DCA.
I think buying Bitcoin by DCA is more preferable to waiting to buy in dip because with DCA you can be monitoring the price and still be investing on a particulate rate over the time and even if the price happen to appreciate instead of dipping as you are expecting you are already in business that will give you a good return which you can add up with the valuable capital to buy more Bitcoin by DCA.
There is absolutely no need worrying your self by always cheeking or monitoring the price of bitcoin when you are already using the DCA strategy for it is gamblers or traders that always monitor bitcoin price so they could sell out if the price is dropping meanwhile the DCA strategy gives you the room to invest at a regular interval by gradually accumulating more bitcoin either every weeks or months weather the price is high or not and continue hodling for long, so always monitoring the price of bitcoin before accumulating Bitcoin is not for DCA users for it is traders or gamblers that always monitor bitcoin price before accumulating Bitcoin.
So far as one have the habit of monitoring and checking the price of bitcoin it means volatility is still a threat. It is only in trading a trader is expected to monitor the market. Bitcoin investment is a longterm investment and you don't have anything to do by monitoring the market, fine if the price of bitcoin goes dip it is just a chance for you to buy more bitcoin and you do not monitor the market to know when to buy bitcoin. As an investors you buy bitcoin at all time you know you afford it and not only in the dip.
The price has nothing to do with hodling and investing bitcoin, if you are considering bitcoin in your hodling it can be a distraction to you and means you still don't have the understanding of bitcoin.
Well monitoring the market is not actually bad in fact monitoring the market has an advantage and a disadvantage which are;
1. It will help an investor to know when there is Dip, just imagine an investor who has been accumulating little by little and have prepared for the Dip, how would the investor know if there is Dip if he or she doesn't check or monitor the market
2. The disadvantage is that if an investor is not strong enough to withstand downtrend or the Dip of the market after investing, these kind of investors may be tempted to sell off the asset because of the Dip and these investors don't sell their holding because they don't understand ... but because of the level of Dip and considering how much they have invested the fear will be much.
However, I doubt your last paragraph, because the price of Bitcoin is what determine the quantity of Bitcoin one will buy in a given period of time, take for instance someone buy's with $1k when the price is $1k and then the price of Bitcoin Dip to $500 it is obvious that the person who buy's at $1k will have 1BTC while some that buy's when the price drop to $500 if he or she used $1k will be having 2BTC so the price really matters.
If you are still buying and holding, the price is not meant to matter to you because you have not sold your investment,
In your second paragraph, it pleases me to bring to your notice that there is no investor that understands the market that will sell his or her investment because of the level of dip, even though there are weak hands but for those who truly understand the market will even tend to maximize such opportunities and buying even more at a cheaper price because it is Bitcoin we are talking about here perhaps one of the reasons why we are expected to invest from our discretionary income is to enable us approach our investment decisions with so much comfort and confident not to be in any form of pressure because the environment is a well known for uncertainty hence it is best we balance our psychology as regards to not making any drastic decisions and end up regretting.