In ODOO version 13, the Enterprise edition, it is possible to bill directly to a customer who buys over the counter using cash or card payment. This can be done by creating a sales order for the customer and then creating an invoice for that order. The invoice can be paid using cash or card payment and can be printed or sent to the customer via email.

To control the sales price and offer the salesperson a range of pricing, you can set up price lists and tie them to the salesperson's user account. You can set up different price lists for different products and assign them to different salespeople, giving them different ranges of pricing that they can offer to customers. Additionally, you can set up rules to automatically adjust the pricing based on certain conditions, such as the quantity of the product purchased or the customer's account.

You may also use the Sales/Margin feature, which allows you to set up a margin percentage on each product, and also gives you a real-time view of the expected margin on each sale, making it possible to adjust the sales price accordingly.

You can also set different pricing for different customers and customer groups, this way you can offer different pricing to different customers or groups of customers.