Checks Unlimited is offering 50% off your entire order of 4+ boxes with code DEAL!
You can also opt for a box of duplicates for only $1 more. If you need checks in bulk, they're also offering your 4th box for free, bringing the cost per box close to $4 each.
My bank charges way more than $5.50 per box. Even Walmart sells them at close to $10 after shipping! This is a great deal if any Hiffers are in the market for new checks.