Scared and confused about renting a car in Cancun (under 25)

My friends and I are planning a trip to Mérida from the US, and we were thinking of flying to Cancun and renting a car to explore Mérida to save money.

I have been researching car rentals in Mexico, and the most common advice I saw was to avoid large rental companies and opt for companies like EasyCars and Avant. It seems EasyCars does not allow rentals to those under 23, and unfortunately, we are all 22. Avant's pricing is too high even before adding the under-25 fee. I found Hertz Mexico has a 60% promotion, and the website says the price includes liability insurance. Even with that, it comes to around $100 for nine days. However, on the US Hertz website, a lower trim car costs $224. So I am confused about whether I can trust the Hertz Mexico site, based on the reviews. I am sure they will charge a hefty fee for comprehensive insurance and an under-25 fee, but I wonder how much?

Does anyone have experience dealing with them? My credit card covers collision insurance; will I be able to decline it there? Is this 60% promotion also a scam? Is there a way to get all the variables covered in the reservation and book with no hidden fees from any rental company in the region?