I did really simple STD magnets, that we made ourselves and mailed out. We are doing the boarding pass invites now ourselves too.
But you can definately skip STDs and just do invites early. my fsil did that for her mexico wedding a couple of years ago and it worked out fine. She also didn't send RSVPs out, that would save you some money too.
How about a STD on evites, that's free. And like morgan suggested vista print does a really good job and they are always having free offers, definately check them out.