The platform that is right for you would vary based on the the kind of event you are doing. There are specific features for large conferences, exhibitions and tradeshows that only certain platforms offer. Pricing comes second to choosing the right platform. Likewise if you are an event organizer doing virtual, in-person & hybrid events you might want the platform to support all three spaces.
The go-to option for beginners into the virtual events space is Zoom. While Zoom is a great choice for small webinars and meetings, you would need a more sophisticated solution for larger conferences and tradeshows. Below is a quick comparison of Zoom & Sarcon.