Ive beaten it 3 times myself, my bro bought in Aug 1995 when it came out. Was not until a couple of years ago I found out not many people did that, its worth like $500 now.
It averages around $180-$220 on eBay for cartridge alone right now. Throw in the player's guide and box and it goes up a couple hundred bucks. I think it only did less than a couple hundred thousand so there aren't a lot of physical copies out there.
This was my first RPG and played it around the time of release too. I didn't own it but my cousin did and that's how I was able to play it. I eventually managed to get a hold of one.