Пусть духи и дорогие, запах у них лёгкий и совсем не резкий.

In Russian, духи meaning perfume is a plural-only noun. This is called pluralia tantum.

So even when English uses singular perfume, Russian uses plural духи.

That is why the adjective is also plural:

• дорогие духи = expensive perfume

A useful comparison:

• духи = perfume
• брюки = trousers/pants
• ножницы = scissors

All of these are grammatically plural in Russian.

It often does mean let, but here it has a different use.

In this sentence, пусть introduces a concession, meaning something like:

• even if
• granted that
• although

So:

• Пусть духи и дорогие...
  means something like
  Even if the perfume is expensive...
  or
  Granted, the perfume is expensive...

This is a common pattern in Russian.

Here и is not the ordinary and. In the pattern пусть ... и ..., it helps reinforce the concessive meaning.

So Пусть духи и дорогие is closer to:

• Even if the perfume is expensive
• Granted that the perfume is expensive

The и adds a sense of yes, that may be true, but...

So the whole sentence has this logic:

• Yes, the perfume may be expensive, but its scent is light and not at all harsh.

In present-tense Russian, the verb to be is usually omitted.

So Russian says:

• духи дорогие = the perfume is expensive
• запах лёгкий = the scent is light
• запах не резкий = the scent is not harsh/sharp

There is no need to add a present-tense is.

This is completely normal in Russian.

Because it agrees with духи, and духи is grammatically plural.

So:

• духи = plural noun
• дорогие = plural adjective

Even though English translates the idea as singular perfume, Russian grammar still treats духи as plural.

Also, here дорогие means expensive, not dear.

Because запах is a separate noun meaning smell or scent.

So the sentence is literally structured like this:

• The perfume is expensive, but the scent it has is light and not harsh.

Even though духи is plural grammatically, it can still have one запах in the singular, because we are talking about the overall scent.

And since запах is masculine singular, the adjectives after it are also masculine singular:

• лёгкий
• не резкий

Yes, literally у них means something like by them / at them, but in Russian this structure is often used to express possession or a characteristic.

So:

• запах у них = their scent / the scent they have

This is a very natural Russian way to say it.

You could compare:

• У меня есть книга = I have a book
• У него хорошее чувство юмора = He has a good sense of humor
• Запах у них лёгкий = Their scent is light

So here у них means of them / their in a natural, descriptive way.

Yes, их запах is possible, but it feels a bit different.

• их запах = their smell/scent
• запах у них = literally the smell they have

In this sentence, запах у них sounds very natural and descriptive. It focuses on the characteristic the perfume has.

Very roughly:

• их запах can sound a bit more directly possessive
• запах у них can sound a bit more conversational and observational

Both are understandable, but запах у них is a very common Russian way to phrase this idea.

With smells:

• лёгкий means light, delicate, not heavy
• резкий means sharp, harsh, strong in an unpleasant way

So:

• лёгкий запах = a light, gentle scent
• резкий запах = a sharp, harsh, overpowering smell

In this sentence, the speaker is saying the perfume’s scent is pleasant because it is:

• light
• not harsh

Совсем не strengthens the negation.

So:

• не резкий = not harsh / not sharp
• совсем не резкий = not harsh at all / not at all sharp

It makes the statement stronger and more emphatic.

So the speaker is not just saying the scent is somewhat mild. They are saying it is really not harsh at all.

The comma separates the two parts of the sentence:

• Пусть духи и дорогие,
• запах у них лёгкий и совсем не резкий.

The first part is a concessive idea:

• Even if the perfume is expensive...

The second part is the main statement:

• ...its scent is light and not harsh at all.

So the comma works a lot like it would in English after a clause such as although or even if.

Yes, духи can also mean spirits in a supernatural or religious sense.

But here it clearly means perfume, because of the context:

• дорогие = expensive
• запах = smell/scent
• лёгкий and не резкий describe fragrance

So in this sentence there is no real ambiguity.

Yes, the word order helps the sentence flow naturally and emphasizes the contrast.

The speaker puts the concessive part first:

• Пусть духи и дорогие...

This sets up the idea:

• Yes, they may be expensive, but...

Then comes the more important point:

• запах у них лёгкий и совсем не резкий

So the sentence structure highlights the contrast between:

• expensive and
• pleasant, light scent

Russian word order is flexible, but this version sounds natural and well-balanced.