It is possible that Bitcoin price reach $250k, but it will soon after that drop under $100k. Also I would speculate that more possible time frame is 24 months and not 12-18.
The same pattern as it did with its past all time highs. $250k is such a huge amount to think of and IIRC, there's one famous crypto guy that has predicted this, Tim Draper.
(
https://cointelegraph.com/news/tim-draper-doubles-down-on-his-250k-btc-prediction)
2017 Bullrun had made this person become famous as he perfectly projected it but I don't think he gonna be right again this time. $250k is really high and never in mind to think we can reach it, ...
$250k per Bitcoin is not high or a lot or impossible. What is not that likely is that it will happen in next 12-18 months. Another thing that is sure is also that price will soon after reaching peak fall down to sub $100k.