Removal of Cheaper Products

Has anyone else noticed cheaper or staple products (orange juice, bin bags, some vegetables, etc..) are consistently unavailable when you book a home delivery or click and collect shop.

I dont mean that the items are missing from the order, rather, it physically won't let you add it to your order.

Every time I've been into the physical shop, the items are always available. Why?

The only thing I can think is that they are removing cheaper items to push online shoppers to more expensive alternatives.