If I purchase a raffle ticket at the $20 level, can I later upgrade to the $50 or $100 level?

No. Once you have made your purchase you are locked in to the ticket level you chose. You cannot upgrade or downgrade to a higher or lower level. We strongly encourage you to read about all of the perks and benefits of each ticket entry level so that you make an informed decision of which level to purchase at that is most beneficial to you.