Advice for getting a 2ds

Hi, sorry I'm new so I don't really know this stuff and want some help. (please)

Please may I have some advice on getting a 2ds and ultra sun for cheap because my old 2ds got stuck drift and has got some home apps (iykyk) and would like to get one for maybe some retro classics but mainly things like shiny hunting in ultra sun before the pokemon bank closure.

My budget is around:

£180-200 (as i just got payed)

Would like to get the cheapest possible:

1.) 2ds

2.) Pokemon ultra sun

Advice would be well appreciated :)

Thanks for reading!