Not right now, price is so high.
Definitely today is not a the right time to buy bitcoin if you are thinking to invest 1 bitcoin and you don't have something to hold to.
But if you already have bitcoin that you holds it is a very good thing to invest in a long term investment with that 1 btc.
No I think you are wrong, if you are a long term investor then you can still afford to buy now, as in future price will be too high and will not be easy to buy bitcoins.
Maybe true maybe not, I think you should wait some weeks before purchasing as the price is expected to decrease in the coming weeks and hence once it gets in high 500's you can buy some bitcoins and hold then till halving.