No one really knows if now or when is the right time to buy, simply because we really don't know how the markets will move in the future. Personally though, I really dislike buying in ATHs(all-time-highs) and I rarely do buy in ATHs. Though if you personally think it will go up in the future, then go ahead.
Well for several days the price is around 8.2k. Do you think it somehow may go down in the following days?
A dip is definitely possible. It's quite common for dips to happen after all-time-highs. But will it happen though? Maybe, but there's no guarantee that it will indeed happen.