Hi ,
You will be happy to know that i already have a product available using which you can set up stores just in a week at max. My product has following modules :
1. admin panel : for admin to manage consumers, manage categories/products, delivery zone management , payment management , order management , coupon management and lot more.
2. Android / iOS / website : consumer front end where consumer can see products , add them to cart, place orders , check offers and do lot more.
All these are already ready we just need to add your data and your live.
Regarding cost i have two options first you can just pay a monthly charge and other wise you can just pay a one time fees.
In monthly charge you dont have any extra cost i will take care of the hosting , sms charges and subscription charge for android app for iphone app you have to purchase the developer account yourself.
Please let me know if you need more details on this.
Regards,
Gargi