I was this close to upgrade to the paid plan, and this is the final push I needed

2FA app, in my case aegis, and a few games

A business card

Just a heads up, ECO tanks do have a sponge inside to collect inks. This sponge needs to be replaced periodically. Once replaced a counter needs to be reset, and that's only achievable through their service (it costs about 50€ where I live). In my experience it seems to be required about every 6000 prints