No, you don’t need a debit machine on your machines but understand that you would be leaving money on the table. Its the convenient for your customers and more likely for them to buy from you if you have all options available
Some parts can be expensive but with the right resources and contacts, you can save a lot of money. You can also get a warranty and insurance on your machinery.
Some people like to buy and then look for locations. some people find locations and then buy vending machines. it honestly depends. for me, i have machinery available first how many days do you or someone restock the machines.