Santa Ana Volcano/Lake Coatepeque

Good morning! I hope all is well. We are in San Salvador until Friday afternoon and would like to visit the Santa Ana volcano and Lake Coatepeque. From what I understand we need a guide to go on the hike; however, the prices online are more expensive than we budgeted for.

We have a rental and can drive to Santa Ana ourselves. Are there guides at the volcano that are a bit cheaper? Are there any other cheaper alternatives we can look into?

For reference, online the price per person is $85-$100.

Thank you in advance.