Amazon has Sensodyne Toothpaste (various) on sale as listed below when you change the quantity to 3 and checkout via Subscribe & Save. Shipping is free w/ Prime or on $25+ orders.
Note you may cancel Subscribe & Save any time after your order ships. This is part of the Get 3 for the price of 2 promotion.
2-Count 4oz Sensodyne Pronamel Toothpaste (Fresh Wave) 3 for $18.94
Note: In stock on July 7 2020.
4oz Sensodyne Pronamel Multi-Action Enamel Toothpaste (Cleansing Mint) 3 for $10.58
4oz Sensodyne Deep Clean Sensitive Toothpaste 3 for $10.58
3.4oz Sensodyne Complete Protection Toothpaste (Extra Fresh) 3 for $10.58
3.4oz Sensodyne Repair & Protect Sensitive Toothpaste 3 for $10.71 -> now 3 for $11.58