As far as I know right now bitcoin price is little bit low and in near future price will rise again. So I think it is best time to buy Bitcoin.
This is a really difficult question.On the one hand, bitcoin is expensive, but on the other (if we consider bitcoin as a long-term investment) , it is undoubtedly very cheap.From what angle you look at it, from that you need to make your choice. I think that now is a good time to buy.