Congrats on finishing your game and publishing it up. Card Shop Kid is full of personality. I really like the dialogue and each character feels like they have their own distinct personality, great job!
I found myself wanting some quality of life improvements, such as the ability to sort or search the card list for the right card, and click through dialogue quicker (only for the dialogue I had already read though).
I like the introduction of the haggle feature. This made it a bit more of a gamble whether to try to haggle or not.
I eventually got a crash, I should have screenshotted this for you but it was some html error and I was playing in the browser. Did you get the save feature working on the downloadable version?
I think you've got a really strong game here, with plenty of options for additional features and improvements.