One page website with detailed ebay and PayPal calculator

I would like a single page website programmed with an ebay profit calculator like - https://www.ebayfeescalculator.com/uk-ebay-calculator/

It's need to be a simple design that can be optimised for mobile. I'd like to be able to customise the website/calculator, in case ebay or paypal change their fees. It needs to have an option for the calculation to be done in Dollar (US), Pound (Sterling) and the Euro.

The calculator should be made up of:

Sold price
Shipping cost
Item cost
Category item is in (fee's could change depending on category selected)
Paypal fee and ebay fee (shouldn't need to be seen as they remain the same)
Shipping charge
Packaging cost

This will then calculate the profit. A nice design feature would be, if it makes a profit, the final figure appears in green and if the final fee is a negative it appears in red.

Also another feature on page would be an ebay planner calculator like https://matthewb.id.au/ebay/eBay-Auction-Date-Planner-Calculator.html

The planner would hap 2 options when you want to begin the auction or when you want to end it. When you put the date and time in, it will show you the time and date it will end in 1.3.5.7 and 10 days.

Also an option for which ebay you'll be listing on US, UK, Germany, Australia, Canada, France and Italy. All with up-to-date fees and categories (check example link above). This can be separate to the calculator or integrated to it.

I would like a email link at the bottom of the calculation, which will enable the results to be sent to the members email address, if they sign up to a mailing list

Additionally but not essential. if you could add multiple rows and have a running total, this would be a nice addition. I'd like so you can only add 5 rows, after that you'd need to sign up to the mailing list.

This is new for me, please forgive, if I've listed in wrong category. Looking forward to answer any questions you may have!