apologize for the lack of information.
1. it is a Nikon D5300. Im using the kit lens 18-35mm and find that even at 18mm it's still not wide enough
2. Budget less than $500, i ok with pre own
3. Yes interior of houses.
Ok, to give an example, due the layout of the house, when taking let's say a living room, I would like to include the sofa set and TV in one single shot at a certain angle. But sometimes the house's layout doesnt allow me to capture these details into a single shot. I thought a wide angle lens might help.
Definitely not looking at fish-eye lenses as the images are too distorted.