I take cash check or card. Customer decides how they want to pay. Cash is a PITA. Pretty soon you are walking around with wallet stuffed with twenties. I hate standing in line in banks, and I don’t like depositing cash in an ATM, but I do it. I like checks the best, you know where they live! You know where they are going to live! They have been pre credit checked and mortgage approved by a bank. I can use any convenient ATM to deposit. I haven’t been stiffed yet. For cards I use square and a cell phone, square scoops 2.75% off the top, but do not charge a monthly fee, unlike your friendly banker. The 10 bucks or so it costs per inspection is partially recouped by not having to go to the bank, the money magically lands in your account within a day, and no ten day hold either.
Avoiding or messing with GST or other taxes is illegal and stupid, especially with the Harper Government, who love finding small time tax cheaters and stomping on them, because it is a lot easier and more satisfying than going after rich corporations with armies of accountants and tax lawyers, who won’t take any poop from government weenies.