nà jiā diàn de dōngxi bú guì, wǒmen qù kànkan ba.

Yes, 家 can mean home or family, but here it is a measure word (classifier).

In Mandarin, many nouns need a classifier when they are counted or pointed out with words like this or that. For shops and some businesses, 家 is a common classifier.

So:

• 那店 → not natural
• 那家店 → that shop/store

You can think of the pattern as:

• 那 + classifier + noun
• that + classifier + noun

So 那家店 means that store.

的 links a modifier to a noun. Very often, it works like 's or of in English.

So:

• 那家店 = that store
• 那家店的东西 = that store’s things / the things from that store / the goods in that store

In this sentence, 的 shows a relationship between the store and the things. It does not always mean literal ownership; here it means the items sold there or the store’s goods.

Because 贵 is an adjective that can act like a verb in Mandarin.

In English, we say:

• The things are expensive.

But in Chinese, adjectives often function directly as predicates, so you can say:

• 东西贵 = The things are expensive.
• 东西不贵 = The things are not expensive.

You usually do not say:

• 东西是不贵 ❌

So in this sentence, 不贵 works like is not expensive.

Yes, the characters literally mean east + west, but 东西 is also a very common word meaning thing / stuff / items.

In this sentence, 东西 refers to goods, products, or the things being sold in the store.

So:

• 那家店的东西 = the stuff in that store / that store’s goods

Also, when 东西 means thing/stuff, it is usually pronounced dōngxi, with the second syllable in a neutral tone.

This is a tone change rule.

Normally, 不 is fourth tone: bù.
But when 不 comes before another fourth-tone syllable, it changes to second tone: bú.

Here:

• 贵 = guì (fourth tone)

So:

• 不贵 is pronounced bú guì, not bù guì

This is a very common rule in Mandarin pronunciation.

不贵 means not expensive, while 便宜 means cheap / inexpensive.

Both can work, but they are not always identical in tone:

• 不贵 often sounds a little softer and more neutral
• 便宜 more directly says something is cheap/inexpensive

So 那家店的东西不贵 can feel like:

• The stuff in that store isn’t expensive

That can sound a bit more natural or less strong than directly saying:

• That store’s stuff is cheap

This is called verb reduplication.

Repeating a verb often makes the action sound:

• casual
• brief
• light
• tentative

So:

• 看 = look / see
• 看看 = have a look / take a look

In this sentence, 去看看吧 sounds more natural and friendly than a plain 去看吧.

Also, the second 看 is usually pronounced in a neutral tone:

• kànkan

Mandarin often uses serial verbs, where verbs are placed one after another without extra words like English to.

So:

• 去 = go
• 看看 = have a look

Together:

• 去看看 = go take a look / go have a look

English needs go to look or more naturally go have a look, but Chinese does not need a separate word for to here.

吧 softens the sentence and makes it sound like a suggestion, proposal, or gentle invitation.

So:

• 我们去看看。 = We’re going to take a look. / We go take a look.
• 我们去看看吧。 = Let’s go have a look. / Why don’t we go take a look?

The 吧 makes it sound more friendly and less forceful.

In this sentence, 我们 naturally includes the listener, because the speaker is making a suggestion:

• 我们去看看吧 = Let’s go have a look.

So even though 我们 can sometimes mean we without the person being spoken to, the context here strongly suggests inclusion.

咱们 is another word that very clearly includes the listener, and in many situations you could also say:

• 咱们去看看吧

That would also mean let’s go take a look.
Whether people use 我们 or 咱们 depends on region, style, and personal habit.

Yes, it is completely natural.

The structure is:

• 那家店的东西 = the things/goods from that store
• 不贵 = are not expensive

So the full clause is:

• 那家店的东西不贵 = The goods in that store aren’t expensive.

This is a very normal Mandarin pattern:

• [place/person] + 的 + 东西 + adjective

For example:

• 这家店的咖啡很好喝。 = The coffee in this shop is tasty.
• 那个人的中文不错。 = That person’s Chinese is pretty good.

So the sentence is not only grammatical, but also very natural in everyday speech.