I have been building simple applications and websites like this one for years. I can make you a website with a How It Works section, Get A Quote section and page, and Contact section (and page or not) where you can update the content yourself and manage all quote requests from the backend if you choose, or just have them emailed to you (however it is preferable to save each submission in a database in case of email delivery failure). Another pro of having these logged is that I can make it so that you can simply enter a price quote amount or range for the entry, along with an optional note, in the backend, and have that generate an pre-formatted reply to the sender. The quote request form can have any and all of specific fields as you need.
Do you already have web hosting? I do prefer to do projects for a fixed price if that works for you. I can have this done within a week. Please do provide any marketing materials (logo, photos, graphics, flyers) you have, if any, and any examples of website styles you like, or we can just figure it out as we go along based on the samples I send. Thanks, I hope to hear from you soon.