So to this end, it's more advisable to focus on the amount you intend to invest and the period of time you intend to invest such amount (probably 10 years or more) instead of focusing on the amount of bitcoin you wish to acquire which could expose you to investing beyond your capacity when the time frame seems too short to achieve same.
Focusing on the time duration of when you will accumulate bitcoin to will not help you build a bigger portfolio, because when the time reaches, you might feel that you have reach your bitcoin goal and stop accumulation bitcoin, whereas, you still have the capacity to continue with increasing your bitcoin investment. It's better that you set a bitcoin target as your accumulation goal so that you can focus and keep your bitcoin investment consistent and ongoing till you reach your bitcoin target.
In future, you might not reach your bitcoin target but you will be close, it depends on how many bitcoin that you set as your target to accumulate. Setting a target make you more committed and discipline if you are serious with your bitcoin accumulation.