Yugster offers a 9-Pack Chinese Sky Lanterns in White or assorted colors for $4.97. Coupon code "FREEYUGBUCK" drops it to $3.97. With $2 for shipping, that's $16 off list, 4 cents cheaper per lantern than our February mention of a 50-pack, and the lowest total price we could find. Each lantern comes with a fuel cell, which can lift the lantern 500 to 1,000 yards. They are also biodegradable.
Note that you should check your state and local regulations concerning the use of these lanterns before purchase.