This is a bit tricky to talk about… first, because bitcoin hasn't even hit one million, and we are no where close to partial adoption, and secondly, because so many things, financially speaking, come off the rails before then.
So, will bitcoin hit one billion dollars per coin? Hell no. No way. It's not going to happen.
… because the dollar dies before then. We will not have FRNs (Federal Reserve Notes) as they are now, around to compare to bitcoin. And, the other reason, by that point, no one will take FRNs in trade for bitcoin.
That said, if bitcoin continued to trade, as it has on exchanges up to now, where there is bitcoin you can buy, AND the FRNs stayed around, yes, bitcoin would easily hit one billion. The banksters would love to move all the derivatives into bitcoin; a trillion dollar market. That would easily push bitcoin over a billion per. The problem here is that the door from the old system into bitcoin will be slammed shut before we ever get to moving the current derivatives market into bitcoin. I doubt that we will even be able to convert REITs to bitcoin before Wall Street falls apart.
All that said, a bag of groceries will probably go from about 20,000 sats today, to less than 1 sat.
Will we be able to compare price before and after the financial reset?
I am really unsure about this. Everything that we typically hold up as something that is the same before and after, are going to change. Probably drastically change.
CPI sucks! It is a basket of goods, that they keep messing with and most of those goods will cease to exist / massively change.
Transportation. How do you compare a wheeled car of today with flying cars tomorrow? There might not be any overlap of prices. As in, the change happens at pretty much the same time. cars = dollars; flying cars = bitcoin. Further, when we move to be with our "family", our tribe, the need for cars drops way down.
Food. You think we could compare the price of a loaf of bread now, to one in the future where bitcoin is a billion, but no. In between now and then everything changes for food. The wheat shortage will have happened, making before and after prices of a loaf of bread impossible. Grocery stores may cease to exist. Your tribe has people who like to make bread, and make them every day, and bake them in solar powered ovens. Because, what they do to commercial breads is evil, downright evil. So, the food before and after will be very different. And food might not even be sold anymore.
Housing. Housing will have completely changed. Suburban homes will have gone to zero. And no one lives in single-family homes anymore. It will all be multi-generational. And it won't be in cities like we have today. Further, they won't be for sale. Real estate, the term, may no longer exist.
So, what can we compare between now and then? Anything we use will be highly tainted, to say the least.
Modern Investments Aren't
All the things that we call investments today will be replaced by bitcoin.
Do you want to invest in this deflationary, decentralized, crypto currency that you have to do nothing to maintain, or all these other risky "assets" that are like gambling on things that are turning to dust, with high maintenance costs?
All of our investment vehicles of today, rely on money printing. Without the asset price inflation caused by money printing, none of these would be "investments".
With a deflationary currency, everything else becomes troublesome. Bitcoin, you can just use. (like we can simply use dollars today) If you want to use stocks, bonds, REITs, real estate, business you have to find a buyer to buy it off of you. The costs in a deflationary world become annoying or worse frustrating on top of losing money.
And so, our modern investments become worth less, while they are also crumbling to dust. No one will buy stock in that corporation that polluted all those places. And no one will buy stuff from that corporation. So, the stock is going to drop and drop in price, maybe into negative numbers (here, i will pay you to take this stock off my hands!) all the while, the corporation is going out of business.
Simply holding bitcoin will be so much better. And sooooo, all these things we currently keep track of, will be useless for price comparison, if they are not gone completely.
Gold & Oil
This one may make it through the financial reset. Although it is going to the price of a shiny yellow metal.
For most of the dollars life, gold's price has been manipulated. So, when the manipulation ends, gold goes up to some ridiculous price. Which messes with all the price comparisons. And then, gold is dropped as a financial asset. Further making price comparisons almost meaningless.
Oil will be even worse. As magnet motors and geothermal energy comes online, and flying cars take over, the need for oil drops. Drops so low that it may become a niche market. Used for making plastics and chemical solutions. Fuel is no longer needed except by guys who like to race old cars. (and in between now and then, there will be so many little wars that the price doesn't stay stable, and so, becomes less than great for comparing prices before and after)
Basically, everything we use nowadays as a yard-stick for price measurement, just stops being such.
And then robotics hits. And then home robotics take over, and manufacturing becomes, "how much time are you willing to wait?"
Everything changes between now and then.
People will say that bitcoin is definitely over a billion dollars per, but without a dollar present, and every other yardstick become useless, we will not really know.
I guess the way that we will know that bitcoin is over a billion:
At a million, a satoshi is worth a penny.
If it is over a billion, a satoshi is worth $10. So, we will know when a satoshi is a meaningful amount of wealth.