I will say Yes , if i only have that amount of money i will buy much bigger than 1 btc , i believe that bitcoin value will increase at $800 in the near future ,just like saving on the bank but this can be a big passive income if that happens in a short period of time.
Yes we should invest our money in bitcoin at a moment, as the price is likely to go high at the time of halving, so if we buy now then we can sell at much higher price.