They are as rich as Abhimanyu because they spend as much as he does. The clothes and jwellery they were wearing during wedding wasn't something someone with financial issues can afford. Abhinav doesn't work, after spending so much on sister's wedding, who could afford not working and living in in law's house and paying for a lawyer's fee? Before moving to Kasauli, Abhinav and Akshara lived in Udaipur for so long without working then Abhinav went to drive one day and had an accident and we didn't see him working after that in Udaipur
When Abhimanyu was in Kasauli, they showed him doing online consultation, he has a hospital so I get how he doesn't have to work and can get break
They have all the money in the world for themselves, it is just that they are poor when it comes to Abhir and they need sympathy for Abhinav.