I’m a little confused, so how exactly does basicstero’s website calculate the price of btc when it’s always changing ?
Well without going into a lecture about currencies and monetary systems, let me simply says this:
There is a BTC to USD exchange rate at any moment and the exact moment you confirm your order there is a known value; that exact exchange rate value of BTC to USD at the moment you purchase is what you owe (this exact BTC amount should be listed on your order confirmation).
Not every source works this way; another source I have used for some items Basicstero does not carry requires me to calculate the amount to send and it is my responsibility that enough is received (i actually need to place an expensive large order with that source but put it off because making payment is somewhat stressful when the BTC to USD exchange is volatile).
*note: I am NOT the source and as such have no authority to set policy or make binding agreements; so this is just to the best of my understanding and from the observation or my own and many others' experiences.
Now, with that said, lets consider the following:
Whenever you go into ANY store or make any purchase in life anywhere, whatever currency the price is listed as is always "changing" relative to all other currencies in the world -- by this I means, you may look at the FOREX, financial news site, and most brokers to see the constantly changing value of the US Dollar (the exchange rate is very important to some that do overseas business, have residence or family in multiple different countries, and/or travel a lot etc).
Every currency is always changing value relative to every other currency. For instance, if you where in Germany, then you would think of the USD changing and have to account for that values fluctuation relative to the Deutsche mark.
Someone in Germany just walks into a store and pays the listed amount, but if you were making an order online from there you also just pay the listed amount but would have to deal with exchanging your USD to DEM which changes (by this I mean, the DEM price in Germany of an item does not change but it is the "price" of DEM in USD that changes -- you first buy the DEM then buy the item using the DEM).
BTC is no different than other currency exchange rates.
Therefore, at the moment you purchase the item, there is a specific BTC price for that item. But the USD relative to BTC is always gaining or losing value so it may cost more or less USD to buy BTC at another moment.
Maybe you do not even deal with USD (you use a different currency in a different country) or all your buying power / liquid assets are stored in actual BTC already instead. OR, you simply have a balance of BTC in your electronic wallet (in which case you do not even buy BTC in real-time for a purchase).
But if you have to exchange USD for BTC, then I suggest doing so as close to the moment you will submit your purchase so there is less time for value fluctuation in the exchange rate. OF course, you can exchange far ahead of time and/or wait until a couple days after etc. if you feel like a gambler; maybe you end up with a rate in your favor, or maybe not, but that is simply being a currency trader / investor.
For your purchase with Basicstero, the BTC amount owed is determined at that moment you make the purchase.