I just ordered my invitations and RSVP cards!
I used that VistaPrint groupon that was advertised a while back ($17 for $70 worth of any product). As luck would have it, the invites, RSVP cards, and the return address labels were all discounted today, and after the groupon, I only paid 10 bucks for my stuff, plus the ~$15 for shipping.
In sum, I got 80 invites, 80 RSVP cards and 140 return labels for 42 bucks. I love groupon, lol.