It took me 2 years to find it, but I finally found someone that sells a 2nd hand Circle Pad Pro XL with a price of about $17. I tested it with
New Nintendo 2DS with second analog stick integrated (Hardware Mod)
Buy Repairs Nintendo New 2DS XL Repairs: Circle Pad Replacement Service | eStarland.com
Nintendo Circle Pad Pro - 3DS Ll/xl Accessory (3DS LL /XL Console Not Included) Japan Import
Nintendo 3DS XL Circle Pad Pro (Nintendo 3DS) : Amazon.co.uk: PC & Video Games
Nintendo 3DS XL Circle Pad Pro (Nintendo 3DS) : Amazon.co.uk: PC & Video Games
Buy Repairs Nintendo 2DS Repairs: Circle Pad Replacement Service | eStarland.com
Circle Pad Pro Supported by Majora's Mask 3D - News - Nintendo World Report
Nintendo 3DS Controllers | eBay
Circle Pad Pro | Nintendo 3DS Wiki | Fandom
2DSXL replacement circle pad seems a bit small, will it still work : r/3DS
Nintendo 3DS Circle Pad Pro
Circle Pad Pro simple and effective fix | GBAtemp.net - The Independent Video Game Community
Weirdness: These Circle Pad Pro Mods Have Some Wacky Designs | Nintendo Life
3DS Circle Pad Pro | VaultNishi
Nintendo 3DS XL Circle Pad Pro - Sonstiges - Two Extra Buttons plus Circle - Walmart.com
Circle Pad Pro | Nintendo 3DS Wiki | Fandom
Nintendo 3DS Circle Pad Pro - NintendoWiki
Nintendo 3DS Circle Pad Pro (Nintendo 3DS) : Amazon.co.uk: PC & Video Games
Circle Pad Pro for Nintendo 2DS Monster Hunter 4 Ultimate Gameplay
Circle Pad Pro built in 2DS | The Official ModRetro Forums
Circle Pad Pro extended slide pad Nintendo 3DS LL Accessory for 3DS LL XL New
