When Kennie pointed out the regular boxes, it wasn't because he knew that Marcus was wanting for money. He mentioned it because Kennie himself that that it was ridiculous to spend so much money on something when it was so easy, and less expensive, to do it yourself. Really, he wasn't out to make people buy the most expensive things in the store for their pets. He preferred that people knew what they were doing and provided the best care they could, that did not always equal the most expensive things.
"Alright, take your pick of the colors and styles. And no need to thank me, I'm here to help with these things." He gave the man a standard Kennie grin. "Is there anything else that I can help you with? Never be afraid to ask. I use to work for the Pet Advisory Board in the Ministry before opening up this shop, so I'm pretty knowledgeable about a whole number of things."