I need to order and send my save-the-dates within the next month, and I'm trying to decide between postcards and magnets. I would prefer magnets because people could stick them on their fridges as a reminder, and for close friends and family it could be a nice keepsake. Postcards, however, would be chaper to make and to mail. Budget is a real concern, but I must do save-the-dates because almost all of my guests are coming from across the country. Opinions, please?