I get the logic behind having an emergency fund before buying Bitcoin, but in reality, it is not always practical,especially for someone with a small or irregular discretionary income. Waiting months to build a fund before getting any exposure can mean missing out entirely if the price moves significantly in the meantime..........imagine someone has $100 left after covering basic needs each month. If they spend five months saving $500 for emergencies before buying any Bitcoin, they risk sitting on the sidelines while the price rises 30 to 40%. Instead, they could put $20 into Bitcoin right away and use the remaining $80 to start building their emergency fund, adjusting the balance as they go. This way, they are in the market early but still working toward financial security.
An emergency fund is still essential because it stops you from panic selling Bitcoin when life throws you an unexpected bill. But it doesn’t need to be fully built before your first satoshi. A balanced approach is buy small amounts of Bitcoin early, build the fund in parallel, and never dip into it for investments... that keeps you both protected and invested.
You're on point mate, it's best to build your emergency fund along side your bitcoin investment, waiting for your emergency fund to get to a specific amount may cost you some good buying opportunities because predicting the move of bitcoin is a bit difficult especially for short term like looking for a buy entry, though it's not necessarily to wait for a dip before you buy, one can buy at any price range as long as his goal is holding for long term. The concept of emergency fund is so we don't get tempted to spend our bitcoin when we face any emergency situation that would require money to be solved, however I love the scenario you gave to save 20% of your discriminate income while 80% is kept as emergency fund. But if the budgeted emergency fund has been realized then it's ok to go aggressive on bitcoin from your discretionary income, let's say 80% while your other 20% could be spent on any other stuff. Maybe saving up to get a hardware wallet just to add extra security to your asset.