It's a shame they're so expensive nowadays. They used to be relatively cheap back in the day. Now there's a million YouTube videos about how you should mod your 3ds so the price has massively spiked.
I would recommend importing one from Japan, but YouTubers ruined that as well.
I can't really recommend getting a 3ds unless it's sub $200. Especially if you're a Mario fan. Imo, 3ds doesn't have the strongest Mario lineup. I would recommend getting one more so if you want to play other Nintendo IPS/third party games.
Zelda and Monster Hunter are absolutely fantastic on 3ds.