My friend wants to gift his girlfriend something nice.

They collect souvenirs , especially if they go out on dates. They are students and don't earn , that's the main reason his girlfriend dislikes expensive gifts.

He was thinking to frame the ticket of the first restaurant they went to with caption like

ink on the bill would fade but our love wouldn't.

They always fight for the possession of that ticket because it was their first date so it's valuable for them.

He's confused that should he save that for later important occasion such as later anniversaries or when he asks her for marriage or something like that or should he gift her on her b'day because you never know how long they'd last.