Where to start explaining? I have no idea but I’ll give it a try.

You could always check WooCommerce and the various addon Plugins that exist for it in case you find straight away what you are trying to achieve.

If you want to approach this by writing your custom code from what I understand you want custom fields for your ‘products’ this means meta_box in WordPress ( for an easier approach on this you could again use plugins like Meta-Box to generate those fields.

All those options your refer to could be linked to a jQuery .change() function so as soon as a customer selects something it refreshes an input box with the correct price.

Hopefully you’ll get a start or a pointer at least on what I think you are trying to achieve here. In case I missed what you are trying to achieve or what the problem is exactly scratch everything, I’m still not sure if you want a full solution or if there’s a specific problem and question ^_^ .

Best regards,
Konstantinos