An intern in my building, overhearing my conversation on this topic with our technology specialist, suggested an alternative that had not occurred to me - my students, already having Gmail accounts, can create documents, spreadsheets, presentations, and more from their iPads with Google Drive - for free! They can also share and upload documents easily, which is perfect for the group projects we are often working on. In addition, the built in spell check and dictionary capabilities of the iPad are still functional within Google Drive, so it a perfect solution for the every day needs of my students. Sure, there are times they will need to create more complex documents, but we do have access to a computer lab once a week. I was looking for something they could use to create simple documents on a daily basis, and this fits that need perfectly as well as fitting my budget.
If you would like to learn more about Google Drive, you can find more information here.