Ni bana son farashi mai tsada a kasuwa.

Word by word:

• Ni – I (independent/emphatic pronoun)
• bana – I do not (habitually / right now). This is ba + na, the negative form of ina (I am / I do in the present).
• son – liking / wanting / love (verbal noun of the verb so “to want/like/love”)
• farashi – price, rate
• mai tsada – expensive, literally having expensiveness
  
  • mai – “having / that has …”
  • tsada – expensiveness, high cost
• a – in / at
• kasuwa – market

So the structure is roughly: I – don’t-like – price – having-expensiveness – in market.

• bana already encodes I (it’s ba + na, where na is “I” in this negative present form), so grammatically Ni is not required.

• Ni is an independent/emphatic pronoun. Adding it stresses the subject:

  • Bana son farashi mai tsada a kasuwa. – I don’t like expensive prices in the market. (neutral)
  • Ni bana son farashi mai tsada a kasuwa. – Me, I don’t like expensive prices in the market. (contrast/emphasis – maybe others do, but I don’t)

You can safely drop Ni in normal speech: Bana son farashi mai tsada a kasuwa.

All are related to the verb so (to want/like/love), but:

• ina son X – I (generally / currently) like/want X.
  
  • This is the normal positive present / habitual.
• bana son X – I don’t (generally / currently) like/want X.
  
  • This is the negative counterpart of ina son X.
• na so X – usually a past reading: I liked/wanted X (on some occasion).

So your sentence uses bana son because it is a negative present/habitual: I don’t like expensive prices …

Hausa very often uses a verbal noun (here son) after forms like ina, kana, bana, etc., especially with verbs like so “to like/want/love”.

• Dictionary/base verb: so – to like/want/love
• Verbal noun: son – liking, wanting, love

Typical patterns:

• Ina son shayi. – I like tea.
• Bana son shayi. – I don’t like tea.

Using bare so here (bana so shayi) is not the standard pattern; you should learn ina son… / bana son… as fixed structures.

The full, very careful negative frame is:

• Ni ba na son farashi mai tsada a kasuwa ba.

Here:

• first ba starts the negation
• last ba closes it off

In everyday speech and writing, the final ba is often omitted when the sentence is simple and clear, and ba + na is usually written together as bana:

• Ni bana son farashi mai tsada a kasuwa.

So both are grammatically possible; yours is the common, more casual version.

• farashi – the price / rate of something (e.g. “the price of tomatoes is 500 naira per kilo”).
• kudi – money, and by extension sometimes “cost/expenses”.

In your sentence, farashi is specifically about price level, not money in general:

• farashi mai tsada – an expensive price, high price
• kudi masu yawa – a lot of money

mai + noun is a very common way to make an adjective in Hausa, meaning “having X / that has X”.

• tsada – expensiveness, high cost (a noun)
• mai tsada – having expensiveness → expensive

Other examples:

• mota mai tsada – an expensive car
• mutum mai kudi – a rich person (person with money)
• abinci mai dadi – tasty food (food with sweetness/goodness)

So farashi mai tsada literally means a price that has expensiveness, i.e. an expensive price / a high price.

Normally, no. Reasons:

• tsada by itself is a noun (“expensiveness”), not a regular adjective.
• Hausa adjectives usually follow the noun and have their own forms (e.g. babba “big”, ƙarami “small”), or you use mai + noun to get an adjective-like phrase.

So:

• ✅ farashi mai tsada – correct and natural: expensive price
• ✅ farashin ya yi tsada. – The price is expensive / has become expensive.
• ❌ farashi tsada – not idiomatic

Basic Hausa word order is Subject – Verb/verb phrase – Object – Other phrases, and location/time phrases often come towards the end.

So:

• Ni bana son farashi mai tsada a kasuwa.
  • Subject: Ni
  • Verb phrase: bana son
  • Object: farashi mai tsada
  • Location: a kasuwa

You can front the location for emphasis:

• A kasuwa bana son farashi mai tsada. – In the market, I don’t like expensive prices.

But the version with a kasuwa at the end is very normal and neutral.

No. Without a, kasuwa is just “market” as a noun, not “in/at the market”.

• a kasuwa – in/at the market
• a cikin kasuwa – inside the market (more explicitly “inside”)

So:

• ✅ Ni bana son farashi mai tsada a kasuwa.
• ❌ Ni bana son farashi mai tsada kasuwa. (missing the preposition)

It is correct and natural. Some common variants:

1. Bana son farashi mai tsada a kasuwa.

   • Drops Ni; this is very common and sounds neutral.

2. Ni bana son farashi mai tsada a kasuwa.

   • Keeps Ni for emphasis on I.

3. A kasuwa bana son farashi mai tsada.

   • Fronts the location to stress the place.

You might also hear a slightly more explicit version like:

• Ni bana son farashi da ya yi tsada a kasuwa.
  I don’t like prices that are (have become) expensive in the market.

But your sentence as given is already quite natural.

The common opposite of mai tsada is mai arha (cheap, inexpensive).

• Ni bana son farashi mai arha a kasuwa.
  I don’t like cheap prices in the market. (grammatically fine, though the idea is unusual!)

If you want the more natural idea I like cheap prices in the market, use the positive:

• Ina son farashi mai arha a kasuwa.
  I like cheap prices in the market.

Use the 1st person plural:

• Mu ba ma son farashi mai tsada a kasuwa.
  We don’t like expensive prices in the market.

Notes:

• mu – we (independent/emphatic)
• ba ma son – we don’t (habitually) like/want

Just like with Ni, you can drop Mu if you don’t need emphasis:

• Ba ma son farashi mai tsada a kasuwa. – also natural.

A few helpful notes:

• Ni – like English “knee”.
• bana – roughly BA-na; both a’s are short.
• son – close to English “son” (short o).
• farashi – fa-RA-shi:
  • r is a tap (like the r in some Scottish or Spanish r).
  • sh as in English “she”.
• tsada – TSA-da:
  • ts is one sound, like the ts in “cats” but a bit crisper at the start of the syllable.
• kasuwa – ka-SU-wa; all vowels pronounced, three syllables.

Hausa is tonal, but for a learner, getting the consonants and vowels clear usually matters more at first; the context here strongly signals the meaning.

By default, bana son … with a bare noun like farashi sounds general / habitual:

• Ni bana son farashi mai tsada a kasuwa.
  → As a rule, I don’t like high prices at the market.

To talk more clearly about specific, current prices, you’d typically say something like:

• Farashin a kasuwa yau ya yi tsada. – The prices in the market today are expensive.
• Farashin kayan a kasuwa ya yi tsada, bana son haka. – The price of goods in the market is expensive, I don’t like that.

Your original sentence leans more toward a general preference.