Another option is to buy a large sheet of paper/card. Depending on your printer, you can get some slightly thicker paper (say, 120gsm), which is still flexible and soft or textured, but comes in a big sheet. For some of the invitations I have done, I found this to be a cheaper options because you cut it to size yourself and print away.
Most stationery places, including Officeworks, Newsagents and craft shops such as Eckerlys and RiotArt stock larger sheets that are textured as well.
Evie K Designshttp://eviekdesigns.moonfruit.com