The Knot Wedding Shop

Etsy has great options! They also have templates that you can download right to your computer to edit with all the details for your wedding! My sister did this and I plan to do the same.

Ann's bridal bargains was perfect for what we wanted and great quality!

I never purchased anything for The Knot Shop, but I do think they get you once you get to the checkout stage. They add “customization” fees, which are HIGH and their shipping is higher than the average. That is how they make up for being able to sell stuff at cheap prices.
If you check Shutterfly during a sale, you can get invitations for an amazing price! We got ours from Shutterfly on a sale and they were gorgeous and fairly inexpensive.

View Quoted Comment Oh wow. That makes sense now. Thank you for letting me know!

Have you checked vistaprint? They tend to have good sales and lovely designs. Otherwise, you definitely want to go with Shutterfly or Minted - they have great sales and you don't want to incur the Knot's fees.

Daughter was extremely happy with Zazzle. There is almost always a 50% or greater coupon (if there's not one today, wait a week or two...), and if you sign up for their Zazzle Black promotion, you get free shipping for a year. Daughter ended up doing all her wedding stationery with them (e.g, invite suite, place cards, signs, thank-you notes, etc.) and everything was great quality, coordinated beautifully. Customer service is excellent, and most things arrived within a week, without expedited shipping. Good luck!

Vistaprint for the win!!!