El te de la botiga és tan barat com el te del mercat.

El is the masculine singular definite article, meaning the.

So:

• el te = the tea

Catalan often uses the definite article in places where English might also use the, and sometimes in places where English might leave it out. In this sentence, both teas are specific ones:

• the tea from the shop
• the tea from the market

That is why you see el te.

Catalan can repeat the noun for clarity:

• El te de la botiga és tan barat com el te del mercat.

This is completely natural.

But Catalan can also avoid repeating the noun if it is clear from context:

• El te de la botiga és tan barat com el del mercat.

Here el means something like the one. So both versions are possible, but the full version is very clear for learners.

Literally, de la botiga means of the shop or from the shop.

In natural English, you would usually understand it as:

• the tea from the shop
• the shop’s tea

In Catalan, de + noun is a very common way to specify origin, source, or association.

So:

• el te de la botiga = the tea from the shop

Because del is a contraction.

• de + el = del

So:

• de la botiga stays de la botiga
• de el mercat becomes del mercat

This is standard Catalan grammar.

Examples:

• de la casa = from the house
• del poble = from the town

So del mercat is just the contracted form of de + el mercat.

Tan ... com is the Catalan pattern for as ... as in comparisons of equality.

So:

• tan barat com = as cheap as

Structure:

• tan
  • adjective/adverb + com

In this sentence:

• és tan barat com = is as cheap as

More examples:

• És tan alt com jo. = He/She is as tall as I am.
• Corre tan ràpid com tu. = He/She runs as fast as you.

Because tan is used before adjectives and adverbs.

Here, barat is an adjective, so you need:

• tan barat

A useful rule:

• tan
  • adjective/adverb
• tant / tanta / tants / tantes
  • noun or quantity idea

Compare:

• És tan barat com l’altre. = It is as cheap as the other one.
• Té tant sucre com l’altre. = It has as much sugar as the other one.

So in your sentence, tan is correct because it modifies the adjective barat.

Because barat agrees with te, and te is masculine singular.

Agreement in Catalan works like this:

• masculine singular: barat
• feminine singular: barata
• masculine plural: barats
• feminine plural: barates

Since el te is masculine singular, the adjective must also be masculine singular:

• El te és barat.

If the noun were feminine, you would change the adjective:

• La tassa és barata. = The cup is cheap.

És is the third person singular of ser:

• és = is

So:

• El te ... és tan barat com... = The tea ... is as cheap as...

It matches the singular subject el te.

A quick reminder of ser in the present:

• jo soc / sóc
• tu ets
• ell / ella és
• nosaltres som
• vosaltres sou
• ells / elles són

Catalan usually uses ser for general qualities or characteristics, including price.

So:

• és barat = is cheap

That is why the sentence uses és, from ser.

Using estar here would sound wrong in standard Catalan, because price is being treated as a characteristic, not a temporary physical state.

The accent in és helps distinguish it from es, which is a different word.

• és = is
• es = a pronoun used in reflexive or passive-like structures

So the accent is important for meaning and correct spelling.

In your sentence, és is the verb:

• El te ... és ... = The tea ... is ...

The sentence follows a very common Catalan pattern:

Subject + verb + tan + adjective + com + comparison

So here:

• El te de la botiga = subject
• és = verb
• tan barat = adjective phrase
• com el te del mercat = comparison

So the full pattern is:

• El te de la botiga és tan barat com el te del mercat.

This is the standard way to say X is as adjective as Y in Catalan.