I got my save-the-dates and part of my invitation suite in the mail this week! But even more excitingly, I checked with the post office, and neither will require extra postage!!!!!! That is a present that I can get excited about! So, I went ahead and bought all the stamps (invitations and RSVPs will be forever stamps), and it all came out to only $100.80!
...I remember a time when I would have had trouble spending $100. The wedding perspective has fully kicked in now though, and it feels incredibly cheap.