Printable Paperie has some of the most fantastic designs for wedding, baby and social invitations. Their prices are quite reasonable if you feel comfortable doing the printing yourself. If not, you can also use a local print shop (my preference). Either way, you can get a totally custom looking invitation for much less than usual.
If I were throwing a summer wedding, I would absolutely be using their Layers of Light Suite. It's airy and so perfect for summer. If blue isn't your thing, you can request a color change ($25 per set). Maybe a buttery yellow or vibrant pink?
PS -Don't forget to head on over to Perfect Bridal and vote for AWS! Vote HERE.