Character Corner is the one with the gift store in the back, right?
I've only been in once, but it seemed fine. Like, the pins are obviously second hand (I'd imagine they buy collections). So if someone that they bought from has a fake, they might not know it? I would assume the vast majority of the HMs were scrappers.
I think if you use the general rules of thumb (no HMs, no bags/boxes/cards over 50%), you'll be fine. They had a few of the 17 inch dolls there, too, last time I went.
The other store on 192, I know for a fact gets their mystery boxes/bags and new releases from the factories in China. She basically told me when I asked how they could sell them for so cheap (some of them were new releases). They SAY they buy them from Disney directly at a discounted price because Disney printed too many of them. But that's BS. These were BRAND NEW series- how could they have printed "too many" when they don't know how they're selling yet? And why wouldn't they just sell them at their own outlets.
It's either the line they feed to customers, or they legit don't understand how "the factory in China" is not the same thing as Disney themselves.
That said, that store does have a good selection of older pins, like you would see at a PTN.