Front-end development of a woocommerce online shop / wordpress

Dear Freelancer, we would like to create an online grocery order platform in Germany with wordpress. We already have the WooCommerce Backend and now need someone to develop the front-end for us. So we would like to offer a small selection of groceries to German customers that they can order online. The ordering process would not be a normal shop, but a little bit different. Everything should be as easy to use and lean as possible. Landing page: We would like to offer our customers to choose from two boxes of a selection of grocery’s, one for like 30 euro, one for like 50 euro , so basically a prefilled shopping cart, once you click on these boxes. On the other side of the landing page we would like to offer the customer the possibility to create their own grocery box through a kind of questionnaire experience. Questionnaire: basically it would be a shop page that is split in 3 individual pages. 1 page would be Hygiene products, the customers can then select from around 10 product and add as many to the card (or in our case box) as they want, then click next and go to the next page food. There we would show them 30 different food items that they can once again select the quantity of and add to the box, then they can click next and then the third page with sweets starts where they can once again add sweets to the box with around 10 products to choose from. Throughout the whole process the customer can see on the left or right top corner what items he already has in his box. He should additionally see that if he goes to around 30 Euro we will send him a small box and if he goes over 50 Euro we will send him a big grocery box. Then when it’s finished they click on checkout and are required to log in with google or facebook and place the order and pay with PayPal or potentially use stripe. That would be all. Everything in the backend would be our current WooCommerce shop. How much would such a front end design cost and how long would it take? We are looking forward to your offers.