It is worth to try right now especially bitcoin price is at a low price, but my suggestion is you buy with a small amount first to see what will happen later. And if the bitcoin price can get down lower, you can buy more bitcoin but don't use all in of your money because we don't know what will happen next. By buying more and more bitcoin at a low price, it means you have an average buying price which can help you to sell when the price can increase later.
I agree, that is a good opinion that if you want to invest again you will start again even in a small amount. But if you think twice just go on to the big amount because it surely that your money will having a good profit.
Well it is not good to be worry about market condition it is very simple to buy at low and sell at high price when you decide to join the market see what will go in your favor investing high amount or low amount and this is the most difficult thing for inexperienced people to take this decision, but its ok those who have trust in crypto currency will invest even at the bottom price, now a day bitcoin is golden coin to invest in 2019 at low price.