Sites like this are also where retailers will send products that have been returned by customers, with multiple similar returned products frequently being bundled into lots and sold in bulk.

So if you're off to the grocery store or warehouse club, you may want to add these items to your buy-in-bulk shopping list. If you make a lot of items from scratch, stock up on baking supplies ...

Our experts recommend stocking up on these items at any opportunity, thanks to their long shelf life and various uses.

Buying in bulk can be more complicated, however, due to storage considerations, and the difference in shelf life between various items. According to Mary Ann Kelley, the meal planning expert ...

But watch out for rookie mistakes that can lead to overspending, such as stocking up on things to avoid making a return trip ...