I have no idea what is in it and I never use it anymore.

Instead I make mushroom dashi with kombu, ginger and dried shittake. It's easy to make and super umami delicious.

a 32 Oz. Broth I use what I need and put the remaining liquid in 8 Oz. Containers and freeze them till I need them. No loss of flavor

Added. I never use canned vegetable broth. I’m allergic to mushrooms. I make my own and freeze smaller amounts.

once open they are subject to spoilage by bacteria. they are almost a perfect medium for growing bad stuff. freeze what you can't use up and it will be fine. I find chicken broth to be fine for at least 10 days if promptly closed and refrigerated.

if you have the freezer space try making your own. the flavor is much better and then you know what is in it. save up veg peels and scraps in the freezer again. I also do this with meat scraps and bones. no need to shop separately just for broth ingredients.

I've used box broth that's been open for close to a month.
Now, that doesn't happen a lot, because most things I'd be using it for uses a whole box.

Beans and rice it is today!

There's an organic low-salt version I get on Amazon. It's a paste that you spoon out. They have a ton of varieties, beef, chicken, mushroom. I've only used the veggie.

https://www.betterthanbouillon.com/products/seasoned-vegetable-base/

Love the roasted onion flavor. They've got a whole line of "culinary" variants. Pretty interesting.

I use it when I don't have time or ingredients to make my own but it isn't low salt in my diet.

I can't get it with any regularity.
A good product.

The 5 days after opening is a food safety precaution, vegtable stock might be good a little longer. I'd suggest freezing it. We put it into ice cube trays. Then we have a bag with scock ice cubes waiting.

First, the 10 days a manufacturer puts on the label has at least a 100% safety marging built in.
Meaning that, sealed & refrigerated, it's actually good for 20 days, as a minimum.
Second, with a clear broth it's easy to detect early spoilage. If it's getting cloudy (beyond what's reasonable for a high salt liquid that's cold)); if in doubt, let it come to room temperature.
Now, I've checked pH of broth and it doesn't change after the box is open. Due to lactic acid formation by bacterial respiration, pH drops as bacterial content rises. Broth should be around a 6.5. If it goes below 6 there's too much bacteria.
But, by that time the broth would start to take on an odor (a bit sour & acrid, in part from that same lacticacid(), so you don't need to check pH. I just have the hardware.
So, sight & nose will tell you what you need, if you go past that 20 days.

costs normally in the US.

Have to compare from my availabilty in Munich. It seems to be around $10 online here.

Safeway: $8.79, on sale for $7.99 per 8 oz jar

Walmart: $4.28 regular price

Hope this helps!

It helps. It gives me perspective on the price from Amazon here.