Spanish often uses the simple present where English might prefer is going up or is increasing.
So:
Both are possible, but the simple present is very common in Spanish for general statements and current trends.
Because sube already includes the idea of it rises / it goes up.
Spanish verbs usually pack the subject information into the verb ending, so a separate word like is is often unnecessary.
In this sentence, sube already means goes up / rises.
Spanish normally omits subject pronouns when the meaning is clear.
Here, el coste is already the subject, so you do not need an extra pronoun.
Adding a pronoun would usually be unnecessary and unnatural here.
They are very similar, but there is a regional preference.
In Spain, coste is common. In much of Latin America, costo is often more common.
So:
A learner of Spanish from Spain should definitely recognise and use coste.
Yes. Subir has both a literal and a figurative use.
Examples:
So here it is being used in the figurative sense of rising/increasing.
Because subir here is being used intransitively, meaning it does not take a direct object in this sentence.
So el coste is the thing doing the action:
Compare with a transitive structure:
There, la empresa is the subject and los precios is the object.
Yes, but the meaning is slightly different.
Coste is cost, while precio is price. They are related, but not always interchangeable.
Yes. The Spanish present tense often covers both ideas.
El coste sube can mean:
Context tells you which meaning is intended.