Unfortunately, pretty much zilch.
Back in 2011 I bought about 500 USD worth of BTC.
I sold out at almost the same price a couple months later as I needed the money.
I did the same a couple of years later.
Of course I needed the money.
Those who say I made a mistake don't understand that current prices reflect future expectations (like fiat currencies or stock market). Nobody has a crystal ball.
Besides, we miss out on many other opportunities in life too. Who could foresee the housing price boom, million dollar pixel web sites, three letter domains, Apple stock price increase etc.
A little luck is needed sometimes.
Well, when you invest money in something that you expect to go up in the long term, but you realize that there is a downside volatility risk, then you create a strategy to invest only from money that you are not going to need to tap into for your living expenses,.... whether that be $10 a week or some other amount that is manageable for you.
You cannot blame that you needed the money on your decision, but instead that you are living without a sufficient cushion in your finances to be able to invest in something, such as bitcoin. I think that most people should be able to build a decent portfolio of a few BTC at these prices, but yeah it's a bit more ambitious to be able to build a portfolio that is 10 0or 20 BTC and takes a lot more time and effort to work with that money in order that you do not have to tap into it.
That's a lot btc.