JIT inventory practices? Sales pressure?

Ideally you want just enough inventory to cover the demand with a little buffer. That way you don’t get saddled with a bunch of shit merch if there is a recall, or a new version is released. Also so you’re not filling your warehouse shelves with stuff that’s taking up space for other products.

Problem is, some weeks people buy more, some weeks they buy less. Also some weeks a shipment doesn’t show up in time, shit gets stolen, shit gets damaged. You can place an order for more inventory to cover the gap, but that takes time to process and arrive.

It’s a very imperfect process with a lot of variables that constantly change.

Because perceived scarcity makes a product more desirable.

I've noticed that while they typically have more stock than the few they are saying, the price tends to go up once the few have been bought up.

So they may say a basketball is 30 bucks with 4 left in stock. When those 4 are bought up, the next band is selling for 35 bucks.

Some drop shippers/manufacturers-on-demand will report to amazon lowish inventory, knowing full well they can get a backorder filled in a day or two, and get the product to you within the same time frame. Or do it the other way -- report that they have way more than they physically have on hand, but can make/backfill within their deadline -- so their listing rises to the top.

There are so many games going on from all the players.

Why should they order more if you're not gonna buy it?

Private sellers selling through Amazon with limited stock of that particular item. Look at the search results your probably going to see the same item from a different source.