Well, for photo realism, 5 minutes will be a lot so you need to account for render time or render costs. That is a little hard to project without knowing your skill set but figure for me I render a frame in around 18 seconds at 1080p. That’s 36 hours to render on my own machine so I have to charge for almost 2 days of work if I render that myself which begs the question, can I profit and is it cheaper to farm it? I give flat rate estimates based on the jobs and scale involved. For a project like yours and the details you provided, models I would charge $500 because I am probably kitbashing some of it and that saves me some time, $250 for lighting because most of it is practical lighting and nothing too crazy. As a walk through you have less room to use hidden or studio lights. $400-600 for materials and UVing depending on how much of the scene can be kit bashed. And if the kit has materials already and their quality. $100 for camera animation, Add $200 for the probably day or 2 of test rendering and trouble shooting. $300 for the rendering. $300 for compositing and $150 for the edit because it should be a pretty straight forward edit. Basic color grading and cuts etc.
All in, depending on the client I would probably charge $2400 average, realistically the price could range between $1500 and $5000 depending on my client and my circumstances, and also just how much of it I am considering a passion project, which you would know better than anyone here.
To be clear, this are MY numbers. Based on your skill level, experience, resources, and ultimately your client and how much you are worth to them, you may get a bit more than 2400 or you might get WAYYYYY less. The other factor is your location. Clients aren’t stupid and they know when they are outsourcing. I know people in Europe and Asia who really can’t charge more than half what I can on a good day to an American client, and I have had the talks about it multiple times. That works the other way to. You should be considerate of clients in countries where the USD is worth significantly more because you might just not be worth it to them. That caveat begins to melt more with your personal skill level and if you are with a studio or agency or if you are personally freelancing but it’s really an issue of experience and good objective self evaluation and just figuring out how far your willing to bend and if it’s reasonable.
It may sound like a lot on paper but realistically, that’s time, and the time til your next job. Your clients are paying for the project time and the time til your next one, and for all the projects you have to pass up because of them, And this is not a small project. Additionally you are likely not working with the large kits and libraries available to larger studios that allow them to keep their prices down proportionally and bust out photo realistic production renders in days. Keeping that in mind I have a friend who works for a studio doing that and they charge WAYYYY more because they typically work in bulk doing 5-20 houses at a time for large developers and charge well into the tens of thousands of dollars. They can do a whole development in a week or 2 but they are a large team with terabytes of libraries at their disposal. Their job is mostly drag and drop, light, link to the farm and render and the next day boom, done. He also gets paid hourly and for all that work he keeps pennys on the dollar because of the resources he has and the stability of the work.