The new iPhone 7 is out. Just look at those sleek curves. Surely, they’re sleeker than the curves on the 6S! You must buy it.

But wait! Before you blow a month’s rent on the iPhone 7 — which will cost between $649 and $969 when it’s available on Sept. 16 — take stock of what you actually need from your device. Are you a power user, whose cell phone is better described as a productivity device? Or is your phone just a texting mechanism you accidentally take pictures on?

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If you’re trying to get the most value out of your phone, it’s good to be honest about what you really need. Late-model phones demand premium prices, and often you’re just paying for the privilege of holding new, but only slightly different bevelled edges.

Instead, take a look one generation back, at the iPhone 6S. Apple just knocked $100 off its retail price, as it usually does when a newer model is released.

You could find even more value on the secondary market. Prices for used iPhones typically drop 15% to 20% after a new iPhone release, according to experts from iPhone resellers Gazelle and Glyde. Another reseller, uSell.com, found a similar 21% drop in used iPhone prices two months after the iPhone 5S was released.

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And what about that 5S? Three years later it’s still an entirely serviceable phone. A cursory inspection of current 32GB iPhone 5S eBay prices indicates that with the predicted 20% drop in price, you’ll be able to pick one up for less than $250. Apple recently discontinued the 5S in favor of the similar-sized iPhone SE (which has similar guts to the iPhone 6S), but you’ve still got a good year or two before the 5S is entirely outmoded.

If you’re buying on the secondary market, you’ll want to make sure the iPhone you purchase is either unlocked so it can work on any network, or is locked to your carrier’s particular network. If your phone is locked to a different network, you’ll have to unlock it before you can use it.

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Stephen Layton is a staff writer at NerdWallet, a personal finance website. Email: slayton@nerdwallet.com.

The article Why Now Is a Great Time to Buy an iPhone 6S originally appeared on NerdWallet.