checkout min. price & checkout without min.price

Hi,

There is no easy setting to do that.

There are two ways to do it:
1. You create two warehouses (one for each section), assign each product from each section to their corresponding warehouse, and you create two sets of shipping methods, one set for each warehouse, and then in the shipping methods of the section warehouse, you can use the minimum price restriction to restrict them to 30€ so that no shipping methods will be able for that section 1 warehouse if there are not enough products of the first section to meet the 30€ minimum price limit.
That can be an issue when people can buy products from the two warehouses at the same time as they'll pay the sum of the shipping fees of each warehouse.

2. You customize the "cart" file of the "checkout" view and add custom code to calculate the total of the products from the first section and refuse the checkout in that case. That's easier to setup and as a developer, I would recommend that solution, but it requires to have a developer to help you do that if you're not a developer yourself.