Free, it's hard to be more frugal than that! Earlier this month we discovered we were out of checks. Sadly it was writing the last check that made us realize there was not another box. We were in a bit of a rush, but because we use cash a lot not as much as others may have been.
Then my memory kicked in and I reminded my husband to order them through the UW Credit Union. We get one free box a year. Much better than the low-cost ones in the Sunday ad section. So, if you use a credit union for your banking needs, ask if they have a free check policy! They offer banking services for free if you maintain a certain balance.