Seconding Padiwaradda! Khun Mae Suam Roy, Mussaya (though the FL's family is also rich lol), and Panthakarn Rak are some other lakorns that might work for you.
Ojakgyo Brothers might be worth checking out also - the FL ends up living at the ML's family's farm after her dad disappears and her rich family becomes not-so-rich. The ML's family isn't really wealthy though, so it's not exactly what you want.
There's also a turkish adaption of Shining Inheritance called Elimi Birakma that's currently airing. It's not a super faithful adaption - they change a lot of things (the relationship development between the FL and ML is much different, it takes longer for the FL to move in with the family, etc.). If you're interested, you can find it on youtube.