It's not a problem! :D

Thanks for trying <3 I'm sorry I keep pestering you, hahah.

Oh! I'm sorry I keep misunderstanding, sadly I do not know how to answer that question.

Ahah, I think you misunderstood again. Sorry to keep bugging you! I didn't mean the DPI of the actual image used, but the effective DPI. At 300dpi, the individual pixels would be invisible. Presumably, in your 300DPI image, each "pixel" was actually many pixels. For example, if each "pixel" was actually 10x10pixels, then that's an effective DPI of 30.

300 DPI

I hope it sells well! What "dpi" was your bookmark, if you happen to know?

Also, I forgot to mention, but the edited AA looks much better!

Oh! :0
Yes, though normally you are not going to sell something that small. But yes, if it is too small you wouldn't be able to read it as pixel art. 
I know when I made my bookmarks the pixels were just the right size before looking like they were too hard to read. This pikachu is a big test  since this is my first time making a buton with pixel art.

With the pixels reading, I meant more the size, not the quality xP I'd imagine there are sizes where the pixels can be too small to really read as intentional, making the whole thing just look "pixelated" rather than "ooh pixel art". Is that something you're encountered or experimented with?

Of the button, no, since I am using a friend's button maker. But I do have some bookmarks that have my pixel art on it. 
Yes, this does include the margins.
https://ibb.co/gOAhkQ
I find really the hardest thing about selling anying pixel art related is making it/resizing it to be pixel perfect and not saving it as a jpeg. (It is better to save it as a pdf or if you can a png but not every printing place takes png.)

Alright, cool, I will fix that in the morning since it is 2am here. Thank you very much!
EditL I fixed the AA, thank you for the critique.

I've always been curious about printed pixel art, how well the "pixels" read and such. Do you happen to have any photos of the physical button?

Does this button include the margins that get folded behind the button? There's a lot of "dead" space, so unless some of that isn't on the front of the button, that Pikachu looks like it might be quite small and not making good use of the available space.

The AA colour on the yellow is too dark, it doesn't so a good job of softening the transition. Making it a bit lighter should help.