When ds was in kindergarten and first grade, we used homemade worksheet savers. His curriculum was much more worksheet oriented than it is now. I purchased an inexpensive pack of three ring binder transparent plastic sleeves. I took the pages out of the workbooks and slipped them into the plastic sleeve, one at a time. Then we worked the sheets writing on the plastic, wiping them off with a damp sponge when we were done.
At first we used dry-erase pens, but they dried out quickly and were relatively expensive. With a little experimenting, I found a large pack of children's multi-colored felt tip pens which wrote well on the plastic sleeves. The large pack of felt tip pens was a no-name brand purchased at Family Dollar for about $2.00, and they lasted a very long time.
Using the sleeve has made it possible for me to reuse these sheets with my next child.
Another way to use the plastic sleeves is to cut two sides and slide it onto a workbook page. This way you don't have to rip the sheets out, or cut the spine away. We secured the sleeve on top with a paper clip, and when ds was done, we had a clean unworked workbook. A few of these unworked books we were able to sell, and some I kept for my daughter.
It's a good way to sample curriculum, and still be able to sell it if it doesn't work out. It's also a good way to stretch your budget if you want to use the curriculum for more than one child.
It was fun looking back over all the sheets we did four years ago, and I even saved our free online printables, and there were quite a few. It's nice to know I don't have to reprint all these, or do the research over again once my daughter begins school.