I found a website that offers 3DS capture card installations. Would you say the prices are fair? These prices are significantly higher than what Katsukitty and Loopy charged if I'm not mistaken :
SALE! NEW NINTENDO 3DS XL Capture KIT Bundle - KATSUKITY CAPTURE | LOOPY USB-C | eBay
3ds capture card loopy for sale | eBay
INSTALL SERVICE - NEW NINTENDO 3DS XL - KATSUKITY CAPTURE KIT | LOOPY USB-C | eBay
New Nintendo 3DS/2DS XL Wireless Capture Card / PC Streaming Service / Twitch | eBay
Grey Original Nintendo DS with Loopy Capture Card installed (Used & Tested) | eBay