There is a ‘genuine’ addition to most items that are moved between borders now, and that is in the freight costs.
Hauliers have to have certain additional paperwork when moving between EU and UK, and they have to be completed by an ‘agent’ (cost), as well as the truck itself now having to include more stops and checks on the way... further adding directly to the truck operating cost. These are of course passed on to the customers! Documents clearance alone, for an artic with one full load from A to B, are running around £100 at the moment. Factor in also that the truck has to stop in Kent (or other) for a few hours and be processed.. adds another £100 or more, and already that truck has easily had 10 or 20% added to its cost (depending on final destination).
Not so sure about the original question (justcartridges), and how that stacks into their pricing model (what they actually import/export), versus other cost increases, but I’ll hazard a guess that there will be a lot of companies trying to increase revenues and profits with the ‘Brexit’ card.
BUT... we were all told this at the referendum, right?!?!?