Rozdíl v ceně je malý.

It breaks down like this:

• Rozdíl = the subject, in the nominative singular
• v ceně = a prepositional phrase modifying rozdíl
• je = is, the 3rd person singular of být (to be)
• malý = an adjective/predicate adjective meaning small, agreeing with rozdíl

So the sentence structure is basically:

[subject] + [prepositional phrase] + [is] + [adjective]

That is very normal Czech word order.

Because the preposition v normally requires the locative case when it means in in a static sense.

The noun cena changes like this:

• nominative: cena
• locative singular: ceně

So:

• v ceně = in the price / in price

This is one of the standard case changes you have to learn with Czech prepositions.

Because malý has to agree with rozdíl.

Rozdíl is:

• masculine
• singular
• nominative

So the adjective also appears in the masculine singular nominative form:

• masculine singular: malý
• feminine singular: malá
• neuter singular: malé

If the subject were different, the adjective would change too.

For example:

• Cena je malá.
• Auto je malé.

It is nominative singular.

That is because rozdíl is the subject of the sentence, and Czech subjects are usually in the nominative.

Also, rozdíl is a masculine inanimate noun.

Yes. Literally, it is in the price, and it is natural Czech.

Czech often uses a prepositional phrase like this where English might prefer a noun-noun combination such as price difference.

So Czech can say:

• rozdíl v ceně = difference in price

A very close alternative is:

• cenový rozdíl = price difference

Both are natural, but rozdíl v ceně is extremely common.

Yes. A common alternative is:

• cenový rozdíl

This uses the adjective cenový (price-related).

The difference is mostly stylistic:

• rozdíl v ceně feels a bit more literal: difference in price
• cenový rozdíl feels a bit more compact: price difference

Both are correct and common.

In a normal sentence like this, je should be included.

Czech usually does not omit the present tense of to be in ordinary statements like this.

So:

• Rozdíl v ceně je malý. = correct
• Rozdíl v ceně malý. = not normal standard Czech

You may see omission in headlines, notes, or very informal speech, but not in standard full sentences.

Yes, Czech word order is flexible, but the neutral version is:

• Rozdíl v ceně je malý.

That sounds like a straightforward statement.

Other orders are possible, but they usually add emphasis or sound less neutral. For example:

• Malý je rozdíl v ceně.
  This sounds marked and emphasizes small.

• V ceně je rozdíl malý.
  This is possible in a special context, but it is not the most natural default wording.

So if you are learning, the original order is the safest and most natural choice.

No. Czech has no articles.

So rozdíl can mean:

• a difference
• the difference

The exact meaning depends on context, not on an article.

That is very common in Czech, and English speakers often have to get used to it.

A simple learner-friendly pronunciation is:

ROZ-deel f TSE-nye ye MA-lee

A few useful notes:

• Czech stress is usually on the first syllable of each word.
• í, é, ý are long vowels.
• c is pronounced like ts.
• v before the voiceless c is often pronounced more like f, so v ceně sounds like f ceně in normal speech.

So the sentence is often heard approximately as:

ROZ-deel f TSE-nye ye MA-lee

You negate je by changing it to není:

• Rozdíl v ceně není malý. = The difference in price is not small.

This is the normal way to negate a sentence with být.

Yes, but that would slightly change the meaning.

• Rozdíl v ceně = difference in price
• Rozdíl v cenách = difference in prices

The singular often refers to price as a general category or to one price comparison.
The plural can emphasize multiple prices or prices in a broader sense.

So in your sentence, the singular ceně is perfectly natural.