Translation:There are very few inexpensive apartments here.
"Málo" is an adverb that must be followed by a noun in the genitive case. For countable nouns, it requires the genitive plural, while genitive singular is used with non-countable nouns.
"Cheap apartments are very few here" is not an accepted translation. Ok. I accept, but then, what is the translation to Czech of my sentence??
The answer shown above is probably the most common formulation in the US, but I wouldn't say that your sentence is wrong in English. See, for example, the second sample sentence at https://dictionary.cambridge.org/grammar/british-grammar/quantifiers/little-a-little-few-a-few. The question is whether your suggestion would be a different sentence in Czech. I will add "Cheap apartments are very few here" IF the Czech natives on the team feel it is appropriate.