I wish I had taken a picture... but I assumed that I could find them online. Alas- I cannot!
I was at the dollar tree over my lunch break, and there were wedding invitation sets for sale. 40 invitations (with RSVP cards and envelopes for both)... for $1!!!! I made sure that was the price, because I was like "WTF... this is the dollar tree, everything is supposed to be a dollar, how are these here?" I asked the worker and she let me know that yes, she could not believe it either, but they were $1. She said they did not have any more than were on display but got them as some random deal.
These kits looked VERY similar to those kits that are sold at Michaels for like $30 or so. They had 4 or 5 different types, and if you are on a budget, looking for some decent invitations... head over to the dollar tree and see if yours has them!