What is the cheapest phone and Koodo plan for me to be able to receive credit card payments from customers, and to make some phone calls, and to check my emails.
Check Huawei Ascend Y330, it should be able to do the basic tasks you need to do and it's cheap. With regards to the plan you are looking for, I would suggest checking TheInformr plan page for list of plans offered by Koodo Mobile. It should help you decide which plan to choose.