My invites went out recently. They were the kind that fold together, held by a ribbon, and had the accomodations card, response card/envelope, and reception card inside. They were done by someone and turned out really awesome. I'm starting to hear back from people that they were really pretty but then some are following up with "Those had to be extremely expensive." One of my dad's coworkers/boss we invited even went so far as to tell him, "We must be paying you too much." and something about the invites must have cost a fortune. I felt really bad when I heard that. How can I respond to these comments rather than "It's really none of your business"?
And here is a blurry version of my invites. It's sitting on two boxes with bows so that isn't part of it. Just the ribbon in the left corner is slid over the invite when it's closed.

Edited because I can't spell.