Prices are way down today. Today might be a good buy day. I thought the prices would drop in Sept. Again I am no expert, I would be looking buy Bitcoin if it fell into the high $3000. if you can hold out I say 3400-3700, but might not go that low. Eth I would be looking in mid 200. Like $240 -250 be good. Litecoin I be looking for $40-50. This is all speculation. I have been waiting for a price drop because when it shoots up it drops historically with a few weeks, then levels out.
When the price of Bitcoin drops every other coin drops too. There are exceptions. You should be setting your phone apps like Blockfolio app so it tells you when the price drops below a certain point. The prices my fall way below what I predict but around those prices when I would be sitting at my computer watching Coinbase dashboard.
If you Jumped the gun and you got some Bitcoin and now it is dropping. I would just ride out this dip in price, or buy more. Since historically It just shoots higher after a big dip. Warren Buffet once said, "buy when people are scared, sell when they greedy."