You have a chance to buy BNB, whether at a low or high price. And if you really want to buy it, you need to wait for a while after the correction can comes again because right now, the price seems high to buy it now.
But maybe I can suggest you trade BNB pair altcoin in Binance, so at least, you will have a chance to earn BNB as a profit.
That will help you to have BNB from trading with the altcoin.
If you keep waiting for price to fall down, and the price goes up, there is nothing you can do, there is no reversal of that, it is gone opportunity and you will be able to do nothing. But, if you buy right now, when its high and the price drops, you could do two things, either buy more to drop the average so you can sell easier when it goes up, or you could simply wait for it to go up again. Do you really think that binance will never be 300+ again? Or 500+ eventually?
I believe all of that will happen, maybe the price will go down at first or maybe it will rise up, but eventually I know that the price will go up a lot and price will be 500+ so I can buy right now, I suggest buying at all prices, and keep buying until it reaches your goal and you can sell after that. Buying right now has plan B, not buying it do not have that hence that is why waiting is not a smart choice.