As far as I know there are plenty of emulators on mobile (android primarily but recently people got some emulators on iphones). If you want to feel physical buttons while still having the games on mobile you can buy a special GB or DS style third party controller for your phone (or any other controller if you do a little bit of finaggling). I can understand that you want to play GBA/DS the intended way but if the money is a consideration I can only recommend you look into the topic of mobile emulators (though I doubt that you need my advice anyways). Hope you find a way out of spending a lot of money on old consoles and games. Have a good day
