I'm assuming it's some kind of shed / cabinet in which you can store and maintain a bicycle.
I'd be happy to answer the questions, but as TJ says, unless it's clear what we're talking about, it's difficult to answer a lot of them – we could be talking about a large shed that you can walk around, or a steel cabinet with a built in workstand. I'd be willing to pay different prices for those two things.
I'd seek to find out what people want first, then work out what can be made, and then present that to try and find out what people would expect to pay / what items you need to benchmark against.
It's early September, so you've got time coming out of your ears 😀