Learn Spanish (Latin America): Si la inflación hubiera bajado, las cosas serían más baratas. - If inflation had gone down, things would be cheaper.

This is a mixed conditional. The first part is a hypothetical situation in the past (inflation didn't actually go down), so we use the past perfect subjunctive (hubiera bajado). The second part is the hypothetical result right now in the present (things aren't cheaper today), so we use the simple conditional (serían).

Prices fluctuate, so why do we use serían instead of estarían for being cheaper?

When describing something as cheap or expensive (barato or caro), Spanish traditionally uses ser. You might hear estar barato in spoken Spanish to emphasize that a price is temporarily lower than usual or on sale, but ser is the standard verb for stating an item's general price tier or value.

Could I say hubiese bajado instead of hubiera bajado?

Yes! Both hubiera and hubiese are valid forms of the imperfect subjunctive for the auxiliary verb haber. However, the -ra ending (hubiera) is overwhelmingly more common in everyday Latin American Spanish.

Is bajar the standard verb for economic indicators like inflation going down?