@KoiwiGal - In that case you might as well make them yourself. If they are invitations for a child's birthday party, I'd get them to make the invitations. Just buy them a bunch of pastel card and appropriately themed stickers, or stencils or whatever else. If the child is old enough, let them loose in a craft store and see what they find (although I would set a price limit first, as some of the fancier card-making accessories can get fairly pricey).
If it's for adults, then think about different kinds of invitations. If it's a vintage ice-cream shop feel you're going for, then get an ice-cream stamp and different kinds of ink (you can even get glitter ink these days). If you can't find ice-cream specifically, you can probably find examples of different flavors, like banana.