Just wondering when everyone buys bitcoin, weekly, monthly or just on the falls? thinking of setting up something regular to ride out the waves..... 
The price of bitcoin is the most unpredictable thing in this world.Because of its primary characteristics no one can tell what will happen with except rare cases (such may be halvings). It is decentralized (so no one can take care of it to help in achieving the staying in a given level) and is yet child (and is such is "capricious" and do what want; if old and mature will be more restrained and cannot go so fast up and down without any kind of rule). Having those in mind the only thing that can be made (at least that is what I do) is to buy every day on every various period little quantity of it. In this way you will not "feel" the costs and will have always more an more.
that the price of the bitcoin will be atleast upto the 800 dollar at the end of this year.
You have a reasonable thought here, in my opinion Bitcoin floor will be at least 800 usd too at the end of the year, so comparing the prediction / speculation to todays price, i believe it is still a good time to buy bitcoin now. Speculators think that there is a big chance that Bitcoin price will rise once the halving occur.