Amazon offers the 3M Scotch Heavy-Duty Packaging Tape with Dispenser 6-Pack, model no. 142-6, for $9.40. Checkout via Subscribe & Save to cut it to $7.99 and bag free shipping. That's a buck under our April mention and the lowest total price we could find for this quantity today by $5. Each roll contains 800" of 1.88"-width tape.
Note: Be sure to cancel Subscribe & Save once your order ships to avoid being billed for subsequent shipments.