I don't know if it's all items, or just the custom square cards and associated items that I use for my game, but the price has increased since I published it.

Production used to cost £12, but now costs £13.20

When I published it, I made sure the price was a nice round £15, but now it's £16.19 in the shop.

Have all the prices gone up?
And why?

Hi EstragonHelmer,

Our production costs have been steadily increasing since we launched and it's now got to the point where we have unfortunately had to pass some of that cost onto customers to keep this service commercially viable.
We apologise for any inconvenience caused by this.

Regards,
Ash.