Learn Russian: Расходы снизились, и товар стал в три раза дешевле. - Expenses decreased, and the product became three times cheaper.

In the structure в + number + раз(а) + comparative, the word for 'times' changes based on the number. Because the number is три, it requires the genitive singular раза. If it were five times cheaper, you would use the genitive plural: в пять раз дешевле.

Why is there a -сь at the end of снизились?

The base verb снизить means 'to lower' or 'to reduce' something (it requires a direct object). Since the expenses (расходы) did not lower something else, but went down themselves, we need the reflexive particle -ся or -сь to make it intransitive.

Is дешевле an irregular comparative form?

Yes. For the adjective дешёвый (cheap), you do not just add the standard -ее ending. It undergoes a stem change, giving us the short comparative form дешевле.

Товар is singular here, but it can translate to 'the product' or 'goods'. How does this word work?

Товар is a countable noun that can mean a specific 'product' or 'item'. However, it is also very frequently used as a collective singular noun to mean 'goods' or 'merchandise' in general, similar to how we use 'produce' or 'inventory' in English.