Das Roaming ist im Preis enthalten.

In this sentence, Roaming is a German noun with the article das, so it is neuter.

With English loanwords, grammatical gender is something you often just have to learn. In the telecom context, das Roaming is the standard form. So:

• das Roaming = roaming

im is a contraction of in dem.

So:

• im Preis = in dem Preis

In English, this is usually translated more naturally as included in the price rather than the more literal in the price.

Because in here takes the dative case.

German in is a two-way preposition:

• it can take accusative when there is movement toward something
• it can take dative when there is location or a fixed state

In im Preis enthalten, there is no movement. It means something like contained within the price / included in the price, so German uses the dative:

• in dem Preis
• contracted: im Preis

Since Preis is masculine, dem is the correct dative singular article.

Here enthalten means included.

The structure is:

• etwas ist im Preis enthalten = something is included in the price

So enthalten is functioning like a past participle used adjectivally, very similar to English included.

You may also see related expressions such as:

• im Preis inbegriffen
• im Preis inklusive

But im Preis enthalten is one of the most common and standard ways to say it.

Good question. Many German past participles do have ge-, but enthalten comes from a verb that does not take ge- in the participle.

Compare:

• machen → gemacht
• kaufen → gekauft

but:

• bezahlen → bezahlt
• verstehen → verstanden
• enthalten → enthalten

So enthalten is the correct participle form here, not geenthalten.

Because that is normal German main-clause word order.

In a standard statement, the finite verb goes in second position. Here the finite verb is ist.

So the structure is:

• Das Roaming = subject
• ist = finite verb in second position
• im Preis = prepositional phrase
• enthalten = participle/adjective at the end

German often puts the non-finite verbal part or predicate element later in the clause, especially at the end.

Yes. That is also correct.

German allows some flexibility in word order, as long as the finite verb stays in second position in a main clause. So both of these are correct:

• Das Roaming ist im Preis enthalten.
• Im Preis ist das Roaming enthalten.

The difference is mainly emphasis:

• Das Roaming... starts with the thing being talked about
• Im Preis... emphasizes that it is included in the price

Yes, very natural. It is exactly the kind of sentence you would see in ads, contracts, travel information, or mobile phone offers.

It sounds standard and idiomatic. In commercial language, German often uses this pattern:

• Frühstück ist im Preis enthalten.
• Versand ist im Preis enthalten.
• Roaming ist im Preis enthalten.

So this sentence is a very useful model to learn.