At just over $2 per tape this 10 pack is the cheapest I've found for brand name miniDV tapes- and free shipping... in fact its the cheapest I've found for miniDV tapes regardless of brand.
Amazon.com: Jvc Mdv60Du10 Mini Digital Video Cassette (10-Pk): Camera & Photo
Amazon.com: Jvc Mdv60Du10 Mini Digital Video Cassette (10-Pk): Camera & Photo