Dramas like New Tale of Gisaeng, Prime Minister and I, Fated to Love you andThe Heirs. Please and thank you :)

Boys over flower , heirs  my favs...
Go to someone's completed list.
Click the Country heading.
Scroll down to South Korea.
Click a drama title.
Enjoy :D
there's even a japanese drama called "Rich Man, Poor Woman"...
Try Moon River, Boss and Me, and Secret Garden

Other dramas that might work for what you are looking for are Noble, My Love, Flower Boy Ramyun Shop, High-End Crush, and Scent of a Woman

Hope this helps!
If you like "Prime Minister and I" and "Fated to Love You", You'll like "Mask" (bit darker) and "Master's Sun". There is also "The Girl Who Sees Scents"

If you like Heirs, you'll definitely like "My Name is Kim Sam Soon", but it's an oldie but a goodie. "Prince of Lan Ling" was also nice. And "Smiling Pasta" was hilarious and romantic - Taiwanese though.
Goong, 
Heard it Through the Grapevine, 
Warm and Cozy, 
Marriage, Not Dating,
High-end Crush,
Cheese in the Trap,
Coffee Prince?
U should check out Sassy Go Go, also know as Cheer up!, I'm not sure that the main couple is far from each other in money , but they have a big difference in education, like the girl is in the bottom of the school and the guy is at the top of the school ( he hangs around rich and smart people so im amusing that his rich ).

Just as a side note Eunji from Apink and N from VIXX from is in here, they both play main roles in Sassy Go Go ( IF UR NOT INTO KPOP THEN DW)