I'm defining a mock e-commerce website on selling airplanes. How should I organize the purchasing part?

This question is for web coders, designers, marketers and anyone who sells airplanes. Most e-commerce websites have the online customer click around until they find something they like. Then all they have to do is click buy or add to shopping cart. But I don't think that is a valid nor realistic process for a website that's selling airplanes... How should I set up my purchasing process on my website?*



*NOTE: Even though this site will be realistic, it will be a MOCK site simply for a student project. I will not be adding every detail into this site, but I would like it to at least appear somewhat ligit. So let's ease the pressure, and keep that in mind when answering.



Assistance to consider in answering this question:

What is the process when purchasing a car from an online dealer site?

http://www.boeing.com/



Other questions that would be nice to have answers to:

How should I display the prices since we're dealing with big money here?

Are there any legal issues that I need to include?

Are there any design solutions for privacy?

______________________________________________________