ebay, use ebay, prices are stupid on there, chronotrigger + super key (converter cartrige) went for a whopping $172 AU, Mario Party 3 and Paper Mario go for $90 au +, around the time of a new release of an existing franchise prices of the older versions go way up, i.e. when Metroid Prime came out, some copies of Super Metroid were going for anywhere between $40-60 AU, but now it only goes for around $30.
actually, keep your games, selling games is bad.