Lol, nice one--and that would actually be a fantastic gimmick for a pet store.  Not kidding about that.

OP, if you really own a pet store I would stick with that if it's profitable for you.  There's nothing quite like owning your own business, and I'm assuming you'd have much less of a pain in your butt as far as regulators go than you would if you tried to start a crypto exchange.  I also don't think another exchange is necessary, because as it stands only the bigger, more trusted ones are used by people who are serious about crypto.  Plus I don't think it's very easy to break into that game anyway.

You'd be better off running a crypto pet store, and I think all you need for that is a payment processor unless you want to receive actual cryptocurrency (which is not what most businesses do).  Best of luck.

Yep, that's exactly what I was thinking.