Groupon has a $50 towards $100 purchase I used for 100 STD 100 invites an over 100 envelope seals totally 118.56, so $68.56 with Groupon. I also bought a personalized stamper for our return address from Groupon (I admit I have a total addiction. Currently waiting on a pair of boots; booked our Vegas trip this past Feb on Groupon currently looking at a honeymoon in Thailand)
We chose the layouts of course edited it to our info. The first one for our STD included a map on the back , front of invite (back includes detailed itinerary of events ceremony Flamingo, Carlos N Charlie's Cocktal, DDB, and The Orleans Reception. Still on the hunt for some decent, cheap envelopes. I will also include map and itinerary in welcome bags.
Note there are very limited Vegas Specific designs, but you can customize whatever ya want!