Rush Charges can double the cost of your invitations.
Room for Error
Order 25 extra invitations and envelopes up front to allow for addressing mistake and additional invitees. You will save money versus ordering extra at a later date.
Skip the reply card and envelopes. Instead, use a postcard that's printed on the same quality of card as your invitations.
If there is room, include reception information on the wedding invitation instead of ordering separate reception cards.