I will not buy now because the price is still higher, but the moment the price fall down to $2k, I will rush to to the market to buy ETH and hodl it like 5years because there is a hope that the price will reach $10k in 5 years time and it will help investors to earn well again.
You don't need to regret it because ethereum will be corrected again when it passes the halving period where you can add to your savings and wait for the next increase which will most likely create a new ATH. After making a profit, you just have to wait for a correction to occur again to save and hold it for another 4 years.