Il prezzo sembra assurdo.

Because prezzo begins with pr-, and Italian uses il before most masculine singular nouns that start with a normal consonant sound.

You use lo only before certain kinds of masculine singular nouns, such as ones beginning with:

• z → lo zaino
• s + consonant → lo studente
• gn → lo gnomo
• ps → lo psicologo
• x, y → lo xilofono

Since prezzo starts with p + r, it takes il:

• il prezzo

Sembra is the third-person singular present tense of sembrare, which means to seem or to appear.

So:

• sembrare = to seem
• sembra = seems

It matches il prezzo because prezzo is singular:

• Il prezzo sembra... = the price seems...

If the subject were plural, the verb would change:

• I prezzi sembrano assurdi.

Because sembrare itself works like to seem in English. It can be followed directly by an adjective.

So Italian says:

• Il prezzo sembra assurdo.

Just like English says:

• The price seems absurd.

You do not need essere here.
A form like sembra essere assurdo is possible, but it is usually more formal or heavier than needed.

Because assurdo agrees with prezzo, and prezzo is a masculine singular noun.

Italian adjectives usually agree in gender and number with the noun they describe or refer to:

• prezzo → masculine singular
• assurdo → masculine singular

Compare:

• Il prezzo sembra assurdo.
• La situazione sembra assurda.
• I prezzi sembrano assurdi.
• Le regole sembrano assurde.

Here assurdo is a predicate adjective. It is not placed directly before or after the noun as part of the noun phrase; instead, it comes after the verb sembra and describes the subject through the verb.

Compare:

• un prezzo assurdo = an absurd price
  (assurdo directly modifies prezzo)

• Il prezzo sembra assurdo. = The price seems absurd
  (assurdo comes after sembra and describes the subject)

Both are correct, but the structure is different.

Yes. That is perfectly correct, but it means something slightly different in tone.

• Il prezzo è assurdo. = stronger, more direct statement
• Il prezzo sembra assurdo. = softer, more cautious, based on appearance or impression

So è sounds like a firm judgment, while sembra leaves a little room for interpretation.

Yes, depending on context, sembrare can often be translated as:

• seems
• looks
• appears

In this sentence, English might naturally use seems or looks, but the Italian verb is still sembrare.

For example:

• Sembra stanco. = He seems tired / He looks tired.
• Sembra impossibile. = It seems impossible / It looks impossible.

So the exact English word can vary, even though the Italian stays the same.

This is the most neutral and standard word order:

• subject + verb + adjective

So:

• Il prezzo sembra assurdo.

Italian does allow more flexibility than English, especially for emphasis, but this normal order is what learners should use first.

For example, you might sometimes hear something like:

• Sembra assurdo, il prezzo.

That can sound more emphatic or stylistically marked. For everyday use, Il prezzo sembra assurdo is the best choice.

A helpful approximate pronunciation is:

• prezzo → PRET-tso
• sembra → SEM-bra

A few details:

• In prezzo, the zz is pronounced like ts.
• The stress in prezzo is on the first syllable: PRÈZ-zo.
• In sembra, the stress is also on the first syllable: SÈM-bra.
• The r in prezzo is lightly rolled or tapped in standard Italian.

The plural would be:

• I prezzi sembrano assurdi.

Each part changes as needed:

• il → i
• prezzo → prezzi
• sembra → sembrano
• assurdo → assurdi

This is a good example of how Italian makes several words agree with the noun.

Yes, it is fairly strong. It usually means something like absurd, ridiculous, or unreasonable, depending on context.

So if you say:

• Il prezzo sembra assurdo.

you are saying the price feels very unreasonable or surprisingly high/illogical.

In some situations, a milder adjective might be used instead, such as:

• alto = high
• esagerato = excessive
• troppo caro = too expensive

But assurdo is very natural when you want to express strong disbelief or frustration.