An often over looked place to source product from is Dollar Tree. Here is something you can find locally or order it online and have it shipped to your local store for free.
Obviously, it cost $1 since it is from Dollar Tree.
Doing a search on Amazon, we find that it is selling for $6.97 FBA.
Plugging those numbers into FBA calulator, we see that not counting inbound shipping cost, we could make about $2 each on these. That is about 200% return.
There is actually another, listing that has a higher sales rank and is an add-on item, but they are getting $9.97 each out of these.
Throw those numbers into FBA calculator and you see that you can profit about $4.83 ( before inbound shipping) We are getting close to 450% on this listing.
You have to be approved for Grocery category and most likely the listing will be combined in the future, but this proves you can source products from Dollar Tree and in this case, return 200-450% on your money.