Actually interior shoot should not charge by hour. Or client will ask you to finish the whole thing within 1-2 hour. If you shoot too "slow" he will also complain. Unless u tell him u will need "x" number of hours to shoot "y" number of photos.
Also if you charge by the hour, he will demand for all the shots that you take and for you to edit all the variations.
So charge by the photo or agree before hand to charge for a fixed number of photos and let him know what is the estimated time and charge. Good to agree on the resolution before hand as well.
Yes, please have a better understanding of the client's requirements before quoting. Things to consider are the expected deliverables, time frame and not forgetting the time you take for editing. Usual charges are about 800 to 1500. I charge separate for prints.
Err you seem to be lost a very fundmental level. What do you what should we give them at the end of the shoot ?? It sounds like you have never done this before at all.
If you are charging money make sure that you can meet client requirements - ie you know what you are doing and can still carry on to do the job when there are major problems at site - ie how to shoot a dark concept room without producing a lite up room ? How to deal with small rooms. How to deal with pixel peeping clients who want 200% can see no pixel breakup but are not willing to pay for you to use a mf digiback to shoot ? How many shots should you take per location ? How bright or dark should the picture tone needs to be. Then you get to the part which is understand what the client expects to get back - they are almost never clear what they expect to see before the shoot but are always vocal about what you should done on delivery. To know what they want when they do not - experience and understand what the industry expects - the key phrasae is "know".
Or you could charge cheap like $100 bucks for the whole thing - yeah it sucks because did I say that depending on how you shoot PP work may or may not be excessive. Then when client ask for too much = tell him you pay peanuts, this is what you get - a monkey behind the camera. Hint most cheapo clients will not complain to you but they complain about you to everyone they know when they get substandard work - they will tell themselves fxxxx okay now I have to pay DI artist 15 times what I paid the monkey to make it right and I make the DI artist sweat blood to give me what I want. No wall in room make me wall. OK my point here is if you think you cannot charge a resonable rate and also able to do a high end job to turn it down. Based on what you are asking you may not be ready for commercail interior work.
for some clients does not know how many shots they really want, there will ask you to shoot as many as you can, but just PAY for those they want in the end, so you may quote for 50 shots, spend the effort of creating the 50 shots, in the end the client will only willing to pay for 5 shots. You lose!
If you quote by day rate, so if the client try to squeeze as many shots as they can within the working hours, they will realize that it is not possible, and cut down to the most important shots or pay for additional hours. This is fair to all.
Sometime, some clients just only need one shot, and they know it may take a few hours or even longer to produce it, so they are willing pay big money for that. Usually, this type of assignments will be given to a very experience photographer, cos to the client, it is too expensive to screw up. The photographer will still be using day rate to quote the job, so the charge will be on par to the effort of creating the shots, this is still fair to all.
Whichever the case, your portfolio speaks louder than anything else. Its just as important to show your clientswhat kind of work you have done before and how competent you are. I always find it easier to negotiate for rates with the portfolio handy. Its easier to justify the amount you are asking for.