is it too late to buy 30xx gpus to mine eth??

It depends until when the bullrun will last, some say will end this year, some say it will go until the end of 2022. You need to understand that if it goes all the way to 2022 then you will have one more year of overpriced gpus everywhere, eth price hitting 5000 usd plus, that will make people bribe factories in china, overpaying by 5x everything like it happened in the end of 2017. The crash eth had in the beginning of 2018 was beautiful, that made 90% of those $800 rx 580 gpus worthless which later on, were sold for $99 or less and there were no people buying it. See my point, it all depends on the market, maybe nvidia and amd is helping to pump cryptocoins but there is a long way to go yet because mining rewards is not good at all, people here saying mining rewards are good then they have no idea what was in the end of 2017 or 2013, 3 usd per 3080 is very low to what we have seen in the end of 2017 which was around 25 usd per card, eth price needs to increase at least 10 times to be comparable to what we had in the end of 2017.
ETH price would have to increase a lot, first it has to go to 0.15 x btc at least, which would be 5x what is right now then it would have to at least drop 50% of the network difficulty right now. I would not count on either, eth 2 just launched and to get to 0.15 x btc it might happen in 2 to 3 years, I dont expect it right now, second too many hidden 8gb asics on eth network, farms in china are ready to add a lot when 4gb gpus and asics are done this December, so forget thinking difficulty will remain lower after December this year than what it is now. Even if a crash happens in the end of this year, eth 2 will bring the hype every year and with hype comes price increase, we might have a bullrun for the next 4 years, a different bullrun, sideways a lot and price increase every quarter or so during those 4 years. Probably eth might never crash like it happened in 2018, is too early to tell. Place your bets trolls hehe
thank you for the explantation. Do you advice to buy and hold eth instead of mining it?