This is a super easy deal to run. If you order wedding invitations (or thank you cards) at Overnight Prints and use the coupon code MARCH50GC then you will get them for 50% off! The invitations come with free envelopes and you can choose one of their designs or you can create and upload your own.
If you shop through Ebates you will get an extra 10% back and $5 to sign up (if you are a new account holder). The final prices on the invitations are as follows:
10 for $4.98 ($4.48 after rebate)
50 for $19.98 ($17.98 after rebate)
100 for $32.48 ($29.23 after rebate)
250 for $39.98 ($35.98 after rebate)
500 for $49.98 ($44.98 after rebate)
That means the invitations are as low as $0.09 each! They do have higher quantities if you are planning a very large wedding. Keep in mind that not everybody will get an invitation (guests and families usually get one invite).
This deal is good through April 1st.