Spices are an indispensable ingredient in countless dishes, which is why customers often question the sourcing and quality of spices before purchasing. However, you can guarantee an upgrade to your spices and your food if you buy from the right vendor — here's what to consider before buying spices from your average grocery store.

Some ground spices last for three to four years, depending on their processing and storage, but eventually, the spices' flavor and potency decline. Grocery stores can keep spices on the shelves for months or even years until their flavor turns dusty and weak, yet supermarkets also sell spices at higher prices than you'd get at smaller vendors.

To buy high-quality spices, consider shopping at ethnic stores, which often sell herbs and spices up to 90% cheaper than grocery stores. Natural food stores or speciality vendors seem more expensive, but allow you to purchase spices in bulk in whatever quantities you need, meaning you can save as much as 97% over brand-name spices.