Need an architectural concept for designing a shopping mall

And how many hundreds of thousands of dollars is your budget for the engineering firm

And I need a concept for my space ship.

Do you realize what you are asking here? You haven't even given us a hint, a suggestion, of what you need or want, and what it's for (college? Work? Job?), how technical it has to be, and in what part of the world.
I will say this: I used to live in Boston, MA, USA. There is a mall that was built on a long narrow swath through the middle of the city where an above ground tram/trolley ran. You can get off the subway and walk for a couple of miles (it feels like) to another stop far across town. Neat 'concept.'