Learn Spanish (Latin America): El precio bajó sospechosamente, es barato barato. - The price dropped suspiciously, it is cheap cheap.

This is a colloquial feature called lexical reduplication. Repeating an adjective emphasizes it to the maximum degree or points to the 'truest' version of the concept. Here, barato barato means it is incredibly cheap or genuinely dirt cheap—even stronger than just saying muy barato.

Since the price just dropped, shouldn't it be está barato instead of es barato?

That is a great observation! Normally, a change in price triggers estar (as in, 'it is cheap right now'). However, by using ser (es), the speaker is making a stronger claim: they are classifying the item itself as fundamentally a 'dirt cheap' thing. This permanent label makes the sudden drop feel even more suspicious.

Quick refresher: how do we form adverbs like sospechosamente?

Adverbs ending in -mente (which is equivalent to the English '-ly') are built from the feminine singular form of the adjective. You take sospechoso, change it to the feminine sospechosa, and add -mente to get sospechosamente.

Why use the preterite bajó here instead of the imperfect bajaba?