Hello.
My name is Alex. I won't bore you with details about me, because those are in my profile.
Regardin your project...
For a commerce web site built on Drupal with cart, order management, order status update, email notification for customers, store management, login/register/ multiple delivery adresses/etc i would charge $450 - $1000, depending on the design, theme, requirements.
Let us discuss this and settle a price and timeline.
Best regards, Alex.