I will say yes, it is okay to invest in bitcoin right now because the price is down again. I don't think that now is too late to invest in bitcoin because you have your time to buy bitcoin at any of price. if you have patience then you can wait the price is down deeply so you can buy a lot of bitcoin but it is depended on how much money you want to use. I think, for now, it is only people which have much of money that could buy 1 bitcoin and the others can only buy with the small amount.