I don't think the law really differentiates between used and new goods, nor big vs small.
It's true that these rules are rarely enforced about you selling an old game to your mate in a bar... But in principle I think any IP rights holders of IP within that game could attempt to block such a sale.
Software liscenses can be re-sold in the EU, but don't ask for specifics.
And again, IANAL, but those import restrictions on grey imports make sense for protecting the offical distribution channels for new goods, e.g. because of warranties and setting sales prices. Used goods don't have warranties, beyond some basic ones, and OEMs usually don't care about those.
It's true that these rules are rarely enforced about you selling an old game to your mate in a bar... But in principle I think any IP rights holders of IP within that game could attempt to block such a sale.