Hi Annette,
Thanks for reaching out! There is not currently a way to display two separate Cost fields on the same event. Sorry for the bad news there! You can however use the free Event Tickets plugin to create RSVP-style tickets on events instead of using the default Cost field, in which case you could include the price in the name of the ticket (note that Event Tickets does not support selling tickets through your site – Event Tickets Plus is required for paid tickets).
Alternatively, you could use the custom fields that come with Pro to create two separate fields for displaying each price. If you go this route, you could then hide the original cost field from the front end via CSS or a template customization.
I’m sorry I don’t have a more straightforward solution for you on this, but please let me know if you have any other questions.
Thanks,
Jennifer