Abonnemanget är en onödig kostnad.

Because Swedish usually puts the definite article at the end of the noun.

• abonnemang = a subscription
• abonnemanget = the subscription

The ending -et shows that abonnemang is a singular definite ett-word.

In Swedish, nouns are either en-words or ett-words.
Abonnemang is an ett-word, so its forms are:

• ett abonnemang = a subscription
• abonnemanget = the subscription

This is something you usually have to learn together with the noun. A good habit is to memorize nouns with their article:

• ett abonnemang
• en kostnad

Because kostnad is an en-word.

So the phrase must agree with kostnad:

• en kostnad = correct
• en onödig kostnad = correct

If the noun were an ett-word, the adjective would change:

• ett onödigt abonnemang = an unnecessary subscription

So here:

• en matches kostnad
• onödig also matches kostnad

Swedish adjectives change form depending on the noun they describe.

With an en-word in singular indefinite form, you use the basic form:

• en onödig kostnad

With an ett-word, you usually add -t:

• ett onödigt abonnemang

With plural or definite forms, you usually use onödiga:

• onödiga kostnader
• den onödiga kostnaden

So onödig is correct because kostnad is singular, indefinite, and an en-word.

This is very natural in Swedish, just as in English:

• Abonnemanget = the subscription
• är en onödig kostnad = is an unnecessary cost

The subject is a specific thing: the subscription.
The complement tells us what kind of thing it is: an unnecessary cost.

Compare English:

• The car is a problem.
• The meeting was a mistake.

Swedish works the same way here.

This sentence has normal Swedish main-clause word order:

• Abonnemanget = subject
• är = verb
• en onödig kostnad = complement

So the pattern is:

Subject + verb + complement

This also fits the Swedish V2 rule, where the finite verb comes in the second position in a main clause. Since the subject comes first here, the verb är comes right after it.

Yes, you could, but it means something slightly different.

• Abonnemanget är en onödig kostnad = The subscription is an unnecessary expense/cost
• Abonnemanget är onödigt = The subscription is unnecessary

The first sentence focuses on the idea of it being a cost.
The second focuses more directly on the idea that it is not needed.

Both are natural, but they are not exactly identical.

Not exactly.

• kostnad = cost / expense
• pris = price
• avgift = fee / charge

So in this sentence, kostnad means that the subscription is an expense you have to pay. It does not mean the listed price in a shop.

Usually it means some kind of subscription, plan, or service agreement that you pay for regularly.

Common examples:

• mobilabonnemang = mobile phone plan
• streamingabonnemang = streaming subscription
• tidningsabonnemang = newspaper subscription

So abonnemang often overlaps with English subscription or plan, depending on context.

A careful approximate pronunciation is:

abonnemanget är en onödig kostnad

Rough guide for an English speaker:

• abonnemanget ≈ ah-bo-neh-MANG-et
• är ≈ a sound somewhat like air, but shorter and more fronted
• en ≈ often a short en
• onödig ≈ oo-NUR-dig or oo-NÖ-dig depending on how detailed you want to be
• kostnad ≈ KOST-nad

A few helpful notes:

• The stress in abonnemanget is on mang
• Swedish ö does not exist in standard English, so learners usually need practice with it
• In normal speech, är and en may sound reduced

Because Swedish usually attaches the to the end of the noun instead of putting it in front.

So:

• subscription = abonnemang
• the subscription = abonnemanget

This is one of the biggest differences from English. Instead of a separate article like the, Swedish often uses a suffix such as:

• -en
• -et
• -na

depending on the noun.

Almost:

• Abonnemanget = the subscription
• är = is
• en = an / a
• onödig = unnecessary
• kostnad = cost / expense

A close literal translation is:

The subscription is an unnecessary cost.

In natural English, you might also say:

• The subscription is an unnecessary expense.
• The subscription is a needless cost.

So the structure is very close to English here.