My company uses Best Checks for our checks and envelopes. They're WAY cheaper than Deluxe or the other big check printers, the quality is excellent, and they're unbelievably fast. We usually receive our orders only two days after we place them! Take a look at www.bestchecks.com.
On the main page, click on To Order on the left, then download the order form. The order form has all the prices and shipping costs listed right on it. I always recommend them to everyone because they make it so simple and easy and their prices are great.