3 Costco Rules You Need to Follow for Maximum Savings

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Most people who join Costco have the same goal -- to save money. And there are plenty of ways to do that at Costco. But if you really want to maximize your savings in the course of your shopping, here are three ground rules it pays to follow.

1. Never buy things just to get a deal

Costco's prices tend to be competitive to begin with. But the warehouse club giant also puts specific products on sale each month so that you're able to reap even more savings on those items.

It can be tempting to take advantage of a great deal at Costco when you see one. But if the item in question isn't something you need, then buying it isn't going to save you money. If anything, it's just going to cost you money.

Right now, for example, you can save $120 on the Bose QuietComfort SC Noise Canceling Headphones. That brings your price down to $199.99, from the usual price of $319.99.

That's a great deal if you actually need noise-canceling headphones. But if you don't, then guess what? You didn't just save yourself $120. Instead, you basically spent $200 for no good reason. Furthermore, if you can't pay for that purchase outright and have to charge it on a credit card and pay it off over time, you could end up paying well more than $200 due to interest charges.

2. Only buy groceries in bulk that your household already eats regularly

A big source of savings at Costco can be the groceries you buy in bulk. But when you buy perishables specifically, you run the risk of having food go bad on you before you've gotten around to eating it. And if that happens, instead of saving money , you've once again wasted it.

So as a rule, only buy groceries in bulk if they're items your family eats on a regular basis. If you have eggs for breakfast three or four times a week, then a bulk pack of eggs likely makes sense to purchase. But if you mostly use eggs for baking, and at best you're whipping up one batch of chocolate chip cookies per month, then eggs are a bulk item you should probably pass on.

3. Always fill up your car while you're doing your shopping

Costco's gas prices are usually among the cheapest in town. So it pays to fill up your car while you're doing your Costco shopping (ideally, before you go in, in case you've got perishable items in your trunk you want to get home as soon as possible).

In fact, it's a good idea to try to time your Costco shopping to when your tank is getting low. Saving even a few cents per gallon could go a long way if you fill up your car weekly, or if you have a larger vehicle that gulps gas no matter how efficiently you try to drive, like a minivan.

Joining Costco could result in a world of savings. But if you want to do your part to maximize those savings, resist the urge to jump on deals, be very careful with bulk grocery purchases, and make filling up your gas tank part of your Costco routine.

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