Put a sticker over it. Sure, the PCB says 2GB, the sticker says 8GB, it was sold as 8GB, how many buyers are going to dig in and really understand what's going on?

That's still trivial to defeat. They're very capable and determined. In the olden days they used to mill the top of microprocessor ie intel x86 to remove the engraving and engrave the fake label. These days I imagine it's way more advanced