I have been there a few times between 2017 and 2019. I would buy a Movistar sim card for still very little, then add a prepaid card of whatever amount was giving the highest bonus and I felt would provide me with data for the majority of my stay. For enough data for one week, assuming you're taking advantage of free wifi where you can, I seemed to spend about $20 total.

I wish there was a way to pre-purchase a sim card before arrival. The ones they sell in a vending machine at the airport I seem to remember were unreasonably expensive, but most places where you can buy a SIM card are closed in the evenings so I had to wait until the day after arrival to get my cell phone up and running.