It is best we buy when there is opportunity to make an Investment instead of waiting for a dip, The market is quite unpredictable, Waiting for that dip opportunity is like someone who is not yet ready to take a bold step to invest in bitcoin assets, and also wasting a grate opportunity to invest aggressively.
I wouldn't support buying when there is an opportunity, it seems like still timing the market to see a favourable price to get started and it is trading rather than investing. I would go with getting started when there is a discretionary income. As long as you have discretionary income available, you need to get started accumulating bitcoin, have a target and plan of increasing your portfolio periodically as more discretionary income comes your way. The best step to success is getting started and in bitcoin, as long as you already have discretionary income, you are good to get started regardless of market condition. You also need to setup backup funds too to protect your investment
You are still saying the same thing that Jostern said and I am not seeing any difference in your post and his. You only misunderstood his statement and think that he is wrong. We can only buy bitcoin when we have the opportunity to buy i.e when you have the money available to buy. It mustn't be from your discretionary income alone. You can be given money that you never expected that is not part of your monthly income, maybe bonus at work for motivation, funds as birthday gifts or you win a jackpot. You can also use that money to invest in bitcoin because you don't have any budget for the money.
Therefore, if Jostern said buying bitcoin is best when you have the opportunity to do so, does not mean that he is timing the market or he is a trader, because he kicked against buying at the dip. However, whenever this is why you are advised to buy bitcoin regularly weekly using DCA so that you don't miss out the opportunities when you have it to buy more bitcoin.