I'v had a one-page website designed that sells a product.
Unfortunately it has not been finished.
I can send you over the design, it just needs finishing and shouldn't take long to do as you can copy what has been done.
The website does have:
1. Live help button
2. Paypal & Google shopping cart
3. Discount facility
4. Embedded youtube video
So you need to know how integrate these in the website.
I also need SEO to be done, so you need to be proficient in SEO.
This website should take less than a week to do as most of the work has been done.