The best opportunity is on year 2010, for now investing is so expensive even when you first publish this post you said btc price os 35k$ the Bitcoin price on year 2010 if i am not mistaken is 1$ there's a month on that year that 1 btc can only buy pizza, look at the very big difference, i hope that you have a strong hands to hold because if you dont you will surely end up losing.
We have to look forward that Bitcoin price is very unlikely to return to the 2010 era, all about the lowest price in the price index record in recent years is part of the history of Bitcoin price journey that continues to grow because of the huge support from the global crypto community, if only the market has hit a drop of $20k so this is the biggest opportunity for me to lock up 80% of my funds in Bitcoin for future assets.