How much should i get for developing such a drupal website

I am now working on a Drupal 7 website for a friend who live in america.
I have designed a custom Drupal 7 bootstrap base subtheme that adapts to many screen sizes including mobiles screens.

With a full website localization (including content translation).
I used views to offer an advanced product search.

the website has 4 user profiles:
seller: has the ability to add product and see a list of his products.
buyer: any registered user in the site is a buyer who can make an order for a custom product or bookmark products.
manager: have the abilities to edit, translate and publish product. manage orders, edit people, and taxonomies terms.

I have installed and configured the website, and it need a little bit of development for front page and other few things am working on.

I hope you could make a look at the website at:

so how much such a work should cost.

and i’ll be so grateful to here your response.

Drupal version: