If you are not going to worry about fees too much, I think the best way is to do it daily, so you are averaging at different prices more and more compared to just one price every week. That's if you have the time to cover it all and understand why you are doing it in the first place. Maybe automate the continuous buying of BTC and stick to a tough time so it could be an experiment to share with those interested in it.
I hope you can update us here with what you plan to do.
I agree with this, subject to the exchange fees not being significantly different I think you would be better buying daily.
Rationale:
1. You will (over time) benefit from the daily fluctuations in price
2. Assuming the buys are made on an exchange the only fees will be the exchange fees for each buy - these are likely to be on a percentage basis and therefore indifferent to one $1400 buy or seven $200 ones;
3. withdrawals to your wallet can be done weekly or monthly as you prefer to minimise network transaction fees