I can see your point...but IMO it's worth it to keep the customer. they ended up buying other varieties. money I MAY or MAY NOT have made if I broke my word. In the long run, in the years to come I may end up making more off him. if the time comes that they don't sell well anymore he may still take a bulk at a couple dollars a piece. a couple dollars is better than no dollars. I may find something in the future that i WILL sell in bulk at the right price and i wouldn't want to burn a bridge
If he already promised them, then he should honor his promise. Reputation and integrity mean more than money.