YMMV on coupon. Amazon has the 34-ct GREENIES Original Large Dog Natural Dental Treats (For Dogs 50 to 100 lbs) on sale for $47 - 5% off with Subscribe & Save (can cancel anytime) - 50% off coupon (click "Save an extra" box) = $21 with free shipping on $25+ or with Prime. Roughly 61 cents per large Greenie.

Other greenies with 50% coupon include: 90-pack Petite Greenies for $21 and 192-pack Teenie Greenies for $22.