For me everything below 50% is an opportunity. I don't look for total bottom because most of us will never be able to predict that. All we can do is choose a level we're comfortable with and be patient afterwards. People who keep searching for the bottom are the ones paying huge exchange fees for buying and selling just to be that 2% closer to the bottom not realizing how much they're losing in the process. I started buying at 35k and kept buying until 29k where I run out of fiat money. I feel comfortable holding this even if we fell lower and I can wait until the next halving.
My minimum target price is $100k. If we won't reach it in 3 years I'll probably rethink my strategy.
There is indeed no such thing as timing the market allthough a lot of people keep trying it. I bought some BTC at around this prize (30k) but my next big buy will be when they go under 20k (which will hopefully not happen anymore). Most of my bitcoins I bought at around 3000$ so I am still in profit.