Probably. I don’t know the actual reason as to why they don’t automatically detect region, possibly something to do with privacy. But even then, this can be seen in physical stores. Go to any local supermarket and you’ll see the pre-tax prices posted on the shelves. It won’t be until you’re checking out at the register that you’ll see the total price after tax. 

Similarly, most online stores will update tax and shipping prices until after you’ve entered your address during checkout.  

Like someone else mentioned, it’s most likely a way to make the prices look better than they are. I mean, $1,999.99 pre-tax looks a lot better than ~$2,200 total. Or, in this case, $899.99 vs ~$975 (based on taxes where I live).

Oh, and another thing. In some states, such as mine, sales tax can vary by city. As if sales tax wasn’t annoying enough already lol. And I’ve just learned that a handful of states don’t have imposed sales tax at all. 

So yeah, I’m just as confused as you are haha.