Create a Woocommerce Custom field/ plugin - PRICE ESTIMATE

I have a niche website selling live seafood and require a price estimate before my products. FOR those who do not understand authorize and manual capture please look for the keywords "manual capture" on this Woocommece document. [login to view URL] Customers ordering process would be: 1. The customer would order a live crab that would that they would agree to buy for $30-$35 2. They would input their credit card details on checkout that would display a price between $30-$[login to view URL] STEP. PayPal would authorise the default price (maximum price). 3. Then in our warehouse we would weigh and pack the crab. In this example the crab will cost the customer $32 4. We would then manually input the price to $32 and charge the customer CAPTURE STEP 5. Deliver the product as soon as the capture step is done The product will have a maximum and minimum price. Example: a crab will be $30-35. It was suggested to me that the maximum price for a product be default regular price on Woocommerce. Thus to display the minimum price it would be a custom field for a product that can be inputted in Woocommerce. Therefore the minimum price is simply an additional piece of text that displays to the customer what price they could be paying. WE CAN pretend the default price on all products is the" maximum price" To further elaborate on this example, if a customer were to buy 2 crabs prices at $30-35 each, then the total cart price would be $60-70. This would also need to be displayed in the cart and checkout pages. As to how much the customer is charged. The maximum price of the cart/ default price will be authorized (PayPal will check if they have $70 to pay for the order). Than when I weigh the 2 crabs in my warehouse the price maybe for example $63. I will capture a lower price to the maximum and weigh the product and charge the customer manually by entering it into Woocommerce. TO SUMMARISE: the purpose of this is because it is not easy to figure out how much each crab can weigh, thus we a customer has book / reserve a crab. By reserving the crab they have agreed to buy the crab at a price estimate (between $30-35 for example). Once the crab has been weighed at my warehouse I will deliver the crab and manually charge them for the specific price it weighs. The minimum prices are simply there to show how much the product may cost, it doesn’t actually effect the default price of the products. This custom field would also need to be compatible for -simple products -variable products -minimum and maximum price range must be visible in the cart and checkout pages -have the choice to show the price range on a product or show the default single price -the total cart price must also be a range. I will also be using Paypal powered by BrainTree to do authorize transactions and manually capture charge on delivery. The maximum price will be authorized. Below will be screenshot examples of what the website would look like with the changes. An additional task has been added to the brief under a word document file. Please also read this carefully