deploys vending machines where your customer will self-serve in making payment before the goods are dispensed; or
deploys kiosks where your customer will self-serve in making payment for completion of transaction with you, such as self-checkout in supermarkets etc.
The cost items you would be looking at comprise:
rental of payment terminal at competitive pricing
transaction fees at competitive Merchant Discount Rate (MDR)
installation fees / setup fees based on implementation requirements
optional items such as digital receipt management system (DRMS), integration with your vending machine, kiosk etc. depending on your business needs