Από τη μία το θέλω, από την άλλη είναι ακριβό.

It is a very common Greek pattern meaning on the one hand ..., on the other hand ....

In this sentence, it sets up a contrast:

• Από τη μία το θέλω = on the one hand, I want it
• από την άλλη είναι ακριβό = on the other hand, it’s expensive

Greek often uses this expression exactly the way English uses on the one hand / on the other hand.

This is about the accusative article τη(ν).

The full form is την, but in modern Greek the final -ν is often dropped before many consonants.

So:

• τη μία is natural because μία starts with μ
• την άλλη keeps the -ν because άλλη starts with a vowel

That is why you get:

• από τη μία
• από την άλλη

You may also hear απ’ τη μία in faster speech.

Both are used in modern Greek.

• μία is the more fully written form
• μια is a very common simplified spelling

So these are both normal:

• Από τη μία
• Από τη μια

Likewise:

• μία μέρα
• μια μέρα

The meaning does not change.

Το is the weak object pronoun meaning it.

So:

• θέλω = I want
• το θέλω = I want it

In this sentence, το refers to some thing already understood from context, such as an item, a product, a car, a phone, and so on.

Because Greek object pronouns usually come before the finite verb.

So Greek says:

• το θέλω = literally it I-want

This is normal Greek word order for weak pronouns:

• τον βλέπω = I see him
• την ξέρω = I know her
• το θέλω = I want it

English puts the object after the verb, but Greek often places these short pronouns before it.

No, not in normal Greek.

The weak pronoun το does not go after the verb in a sentence like this. You say:

• το θέλω

If you want a stronger, more emphatic form, you could use:

• θέλω αυτό = I want that / I want this one

But that is not the same as the usual clitic pronoun structure.

Greek often leaves subject pronouns out because the verb ending already shows the person.

Here:

• θέλω already means I want

So εγώ is unnecessary unless you want emphasis or contrast.

For example:

• Εγώ το θέλω = I want it

That sounds more emphatic, as if contrasting with someone else.

Greek frequently omits subjects when they are clear from context.

Here, the thing referred to by το in the first clause is still understood in the second clause, so Greek simply says:

• είναι ακριβό = it is expensive

You could say:

• αυτό είναι ακριβό

but that would be more explicit or emphatic, similar to saying that is expensive.

Because the thing being talked about is understood as neuter singular.

The pronoun in the first clause is το, which is neuter singular, so the adjective matches it:

• ακριβό = neuter singular
• ακριβός = masculine singular
• ακριβή = feminine singular

Examples:

• Ο υπολογιστής είναι ακριβός = The computer is expensive
• Η τσάντα είναι ακριβή = The bag is expensive
• Το κινητό είναι ακριβό = The phone is expensive

In your sentence, the noun is not repeated, but the neuter idea is still there.

Its most common meaning in a sentence like this is expensive.

Depending on context, ακριβός / ακριβή / ακριβό can also mean dear, precious, or even accurate/exact in some expressions, but here the natural meaning is clearly expensive.

So in this sentence:

• είναι ακριβό = it’s expensive

It is a fairly fixed expression, so learners should treat it as a set phrase.

The standard pattern is:

• Από τη μία ..., από την άλλη ...

That is the most natural and idiomatic order.

You might hear small variations in real speech, but as a learner, this is the version to remember and use.

Yes, από normally means from, but in this expression it is part of an idiomatic phrase.

Word for word, από τη μία / από την άλλη looks like from the one / from the other, but you should not translate it literally here. As a whole, it means:

• on the one hand / on the other hand

So this is a good example of how a very common preposition can be part of a fixed idiomatic structure.

In writing, the comma is natural and helpful because the sentence has two contrasting clauses:

• Από τη μία το θέλω, από την άλλη είναι ακριβό.

It marks a pause and makes the contrast clearer.

In speech, you would normally pause slightly there as well.