Packaging And Embellishments: If you're adding embellishments, or you're mailing more than just an invite plus an RSVP card (we opted to mail more info, because of the destination aspect), keep track of the weight of your invitation suite once it's all packed up. Depending on its size, you may be facing more postage fees than a simple stamp will cover. You can get a postage estimate using a kitchen scale and checking on the USPS website. Through the USPS website I also learned that square invites and envelopes cost more in postage, by a significant amount. It's not worth it.
AT_HOME PRINTING: By far the most accessible, this is easiest option for tackling the project in smaller chunks on weeknights rather than spending hours in a studio or waiting at a print shop. However, you should test paper before buying a ton of it, printers can be especially finicky, and your can't exactly change the ink your printer uses. If your printer isn't higher end, you may have very limited paper options. Here's a little more on at_home printing.