lastly if the funds is not stable don’t pressure your investment even if it takes more than 4 or 5 years to build your desired portfolio.
I believe that 4-5 years is a short timeline for a new beginner who is still in his late twenties of early thirties to use in accumulating bitcoin to his desired quantity. It's better that a new investor should think of accumulating bitcoin for three circles and above so that he can have enough time to build his portfolio to a good size in future using DCA method and by supplementing it with buying at the dip and lump sum when possible.
I believe that even if you frontload your bitcoin purchase in order for you to accumulate a decent size, a circle isn't enough because you don't need to stop buying until you have reached your bitcoin target or be in your over accumulation stage.