I bought the Waterpik Ultra Pro from the last deal and I really like it, however the replacements are expensive (as expected). Amazon AU has the storage kit with 6 tips (2 regular, 2 plaque seeker, 2 orthodontic) as part of the buy 3, get one free (https://www.amazon.com.au/gp/promotion/AFJAOQZX19CV3) promotion that ends today. Plus free expedited international delivery for Prime.
The orthodontic tips aren't useful for me, but the 2 regular tips alone at shavershop are ~§20 (https://www.shavershop.com.au/waterpik/orthodontic-refill-2p...), making it ~$60 just for 6 regular tips. So with this deal, I am getting the 6x plaque seeker tips, 6x orthodontic tips, and 3x storage cases for free (and I'm paying $7.50 less). That's a winner, imo. Sign up for free Prime trial if you haven't already done so.