I actually have quite a few rare games, some of them I got at secondhand game stores, some I've had since I was a kid, and others I bought on release. The only one I bought off of ebay for way too much money was Dragon Quest V.
Persona Q2 New Cinema Labyrinth (physical copy with case is roughly $80-90, found it for like 30 bucks at a gamestop)
Yo-Kai Watch 3 (physical copy is $90-110, bought new on release)
Dragon Quest VIII 3DS ($65-70, got it new from Best Buy)
Shantae and The Pirates Curse (65-75, ordered a copy on Mercari for 40 bucks)
Dragon Quest IV Chapters of The Chosen DS ($80-90, got it for my 9th birthday as a kid)
Dragon Quest V DS ($80-90)
Some other games I've always wanted to own but probably never will include Earthbound on the SNES, Dragon Quest VI on the Ds. Chibi-robo on gamecube, Fire Emblem Path of Raidance on gamecube, and Shantae and the 7 Sirens on Switch are all ridiculously expensive to own though, so I'll probably wait for virtual console releases,