You can figure US$30-some each way at the the official rate, although things fluctuate so much - when there's a price adjustment, it can be closer to $40, before the next adjustment, it is closer to $20. This has been the typical range for years. (My March trip was about $17 at the "blue.")

Easiest bet is upon arrival, just suck it up (i.e., pay the official rate) with a credit card and get a car service from one of the services just past the customs door - they'll bring you right to your car, and then right to your lodging. For the return, you'll have "blue" $. You may enjoy using the "Cabify" app there as you can set it to pay cash, but you will also be able to set your pick up point and destination without language issues, and the prices are typically decent. Also, don't rely on the GPS - always type in your street address (street name then number) for the pickup point.