He was willing to BUY the bags as he always has in the past. You’re fine to use the cardboard. Which, BTW, means it won’t be recycled as it always is by the store.
I think he’s right to resist the ‘nudge’.
Why assume that it is a “nudge”, caused by some vast green conspiracy? If they were making money off of the bags, I very much doubt that they would stop selling them. If they stopped carrying them in his store, chances are that they weren’t selling enough for the practice to be cost effective. You have to accept that by going to budget stores like this instead of regular ones, there will be tradeoffs, like a lack of rainchecks and minimal weekly sales. Or a lack of plastic bags.