Der Verkaufspreis ist mal günstig, mal teuer.

In this sentence, mal ... mal ... means sometimes ... sometimes ... or at one time ... at another time ....

So:

• mal günstig, mal teuer = sometimes cheap, sometimes expensive

It shows that the selling price is not consistent. It changes.

This pattern is quite common in German:

• Mal regnet es, mal scheint die Sonne.
  = Sometimes it rains, sometimes the sun shines.

It does not mean times here in the math sense.

It is the same word in spelling, but the function is different.

In Komm mal her, mal is a modal particle. It softens the command a little, making it sound more natural or less abrupt.

In mal günstig, mal teuer, mal is part of a fixed pattern meaning sometimes this, sometimes that.

So:

• Komm mal her. → softening particle
• mal günstig, mal teuer → alternating situations

Learners often notice mal everywhere in German, because it has several uses.

Because they come after the verb ist and describe the subject. In this position, German adjectives usually stay in their basic form.

This is called a predicate adjective.

• Der Verkaufspreis ist günstig.
• Der Verkaufspreis ist teuer.

No adjective ending is added after sein.

But if the adjective comes before a noun, then it does take an ending:

• der günstige Verkaufspreis
• der teure Verkaufspreis

So the difference is:

• ist günstig / ist teuer → no ending
• der günstige / der teure Preis → adjective ending required

Because the main noun is Preis, and Preis is masculine in German:

• der Preis

Verkaufspreis is a compound noun:

• Verkauf = sale
• Preis = price

In German compounds, the last part determines the gender. Since Preis is masculine, the whole word is masculine:

• der Verkaufspreis

This is a very important rule for German compound nouns.

Because German normally writes compound nouns as one word.

So English may write:

• selling price
• sale price

But German often combines such ideas into one noun:

• Verkaufspreis

This is very normal in German. Other examples:

• Haus
  • Tür = Haustür
• Arbeits
  • Zimmer = Arbeitszimmer
• Schoko
  • Kuchen = Schokokuchen

And because it is a noun, it is also capitalized:

• der Verkaufspreis

After ist, German can list two contrasting descriptions of the subject.

Here, the pattern is:

• ist mal X, mal Y

So:

• ist mal günstig, mal teuer

This creates a neat, balanced expression meaning the price varies.

A more expanded version would be:

• Der Verkaufspreis ist manchmal günstig und manchmal teuer.

That is also understandable, but mal ..., mal ... sounds more idiomatic and compact here.

Yes, that is a very good translation.

A natural English version could be:

• The selling price is sometimes low, sometimes high.
• The selling price is sometimes cheap, sometimes expensive.
• The selling price varies: sometimes it’s cheap, sometimes it’s expensive.

Since the meaning has already been given to the learner, the important thing to notice is that German often uses mal ..., mal ... where English might use sometimes ... sometimes ....

You could use billig, but günstig is usually the safer and more natural choice.

• günstig = inexpensive, favorable, good value
• billig = cheap, but often with a negative sense like low-quality or tacky

So:

• günstig sounds more neutral or positive
• billig can sound more critical

That is why günstig is often preferred in everyday German when talking about prices.

Not exactly.

• Preis = price in general
• Verkaufspreis = selling price / sale price

So Verkaufspreis is more specific. It refers to the price at which something is being sold.

Depending on context, German might also use other words, for example:

• Kaufpreis = purchase price
• Einzelhandelspreis = retail price
• Listenpreis = list price

But in your sentence, Verkaufspreis clearly focuses on the price for selling something.

Yes. You could say:

• Der Verkaufspreis ist manchmal günstig, manchmal teuer.

This is grammatical and clear.

But there is a small stylistic difference:

• mal ..., mal ... sounds more idiomatic, compact, and rhythmic
• manchmal ..., manchmal ... sounds a bit more explicit

In many everyday contexts, native speakers would prefer mal ..., mal ... for this kind of contrast.

It is pronounced like mahl.

Very roughly for English speakers, it sounds like:

• mahl

The a is long, not short like in English mall for many speakers.

So:

• mal günstig, mal teuer

Both mal words are pronounced the same way.

Usually, yes. It suggests that the selling price is not always the same. It may be cheap at one time and expensive at another.

However, the exact reason for the variation is not specified. It could vary because of:

• time
• market conditions
• seller
• product version
• place

The sentence only tells you that the price alternates between being favorable and expensive.