Yeah, i doubt i'll sell them either, I personally dislike secret of mana myself, but I'm holding onto it for completeness sake.
I've found the majority of my games in different gaming stores around the country, but the very large majority i bought from people in school for deals that are amazingly good. (Chrono trigger for free was from a friend of mine) Similarily, i spent $20 and bought all 3 donkey kong countries, while another $20 bought me Super Ghouls'n'ghosts, Super Metroid and Super Gameboy. awesome deals like that helped me achieve the amazing snes collection i own. I always keep about $20 on me and I always check the used SNES games before i buy anything new. Just this last weekend I bought Illusion of Gaia for $10 because it was hiding in a bin at EBgames. (Same bin had some great titles like Kirby: Super Star in it, but i already owned them)
Sometimes you just need to know what to look out for and you get lucky.
This is already horribly off topic, probably best to make a new thread to discuss SNES titles.
edit: found the other thread, its in other systems. Go there ^_^