Ok, actually I think they're pretty cheap right now. You should maybe consider buying one second hand on eBay or something, although you have to be careful there. Anyways, good luck getting one! PS. Maybe you should hit Christmas, they're always on sale then, at least by me xD
And here I thought I was the only one. I also don't have a 3ds. I've fallen so far behind these Pokémon games. I've only played the first three generations. Maybe I'll get one for myself later this year, but for now, Red, Gold, and Ruby are my go to games.
They probably will go on sale soon seeing that the Switch will be the next big thing this upcoming holiday! Maybe you can get one then! ^^
just from digging around online, the cheapest that I can find that isn't a used 2DS is around $110+ shipping, which isn't a lot in the grand scheme of things, but it depends on your saving habits. like the others have mentioned above, i'd be more on the lookout for 2ds/3ds deals, but moreso the former than the ladder since 2ds systems are usually cheaper.