If you've got your heart set on a new iPhone X, but can't stomach the idea of paying $999, there's no shortage of deals out there for people willing to trade in their old iPhones.

In fact, many offer hundreds of dollars in discounts. But just about all of those options come with big catches.

"Consumers need to take a minute and evaluate their needs," says Scott Peterson, an analyst who tracks smartphones for the retail market research firm Gap Intelligence. "Stores will help you do that, but don’t get fooled by the razzle-dazzle of the deals."

In the end, shoppers may find they don't qualify for the deals and then get sucked into buying the phone anyway. It's confusing, Peterson admits.

Here's a clear-eyed look at some of the best iPhone X trade-in deals available right now.

Carriers

These offers generally have the most conditions. In some cases, they apply only to new customers or customers who wish to add a new phone line. And most carriers stretch the payments—as well as the discounts—out over a period of time. Bail early and you risk forfeiting those discounts and being forced to pay off the phone.

And, as with other enterprises that accept old phones, carriers won't take a device that isn't fully paid off. That means you're likely going to be on the hook for any outstanding balance, even if it simply gets transferred to the new deal.

Those who negotiate the trade-in terms online need to keep in mind that the discounts also hinge on you delivering the old phone in the condition you promised. So don't say it's in excellent shape when, for example, the screen is cracked. If a buyer thinks it’s not up to snuff, you may end up with less money or no deal.

If you're thinking about changing carriers in hopes of getting a bargain, you may also want to consult our roundup of the best low-cost cell-phone plans for information on how to weigh each offer.

Sprint: If a customer finds a better deal than this one within two weeks of buying the phone, Sprint says it will match the price difference with a cash gift card. The company is offering new or existing customers who hand off any Apple iPhone dating back to the iPhone 6 an 18-month lease on an iPhone X for $22.22 per month. (The deal is open to those who own certain Android phones, too.) Once that 18 months is up, you give the X back or buy it outright by paying the standard lease price of $41.67 per month for six additional months.

That basically gets you an iPhone X for about $650. But, beware, if you leave Sprint before that 18 months is up, you'll have to pay the remaining cost of the phone.

Verizon: This carrier offers up to $300 off the cost of an iPhone X for the trade in of an iPhone 7, 7 Plus, 6s, or 6s Plus. (It will accept some of the latest high-end Android phones, too.) But, you have to sign up for one of the company's unlimited plans, which start at $80 per month for a single phone. You also have to pay the new iPhone off over a two-year period. And that $300 savings? You don’t get it all at once. It's delivered to you in credits over the two years, which works out to about $12.50 per month.

T-Mobile: The carrier will also give you up to $300 off an iPhone X, 8, or 8 Plus for trading in a model dating back to the iPhone 6. Once again, you have to pay for the new phone over a two-year installment plan and the $300 discount comes in the form of bill credits over that time period.

If you cancel your T-Mobile service during that span, you may have to pay the remaining balance on the phone and forfeit the discount credits.

AT&T: This carrier doesn't have an iPhone X-specific trade-in deal, but it does offer credit for older models. On October 26, the offers for an iPhone 7 with 32GB of storage ranged from $200 to $230 depending on the carrier the phone is currently assigned to.

Apple and Others

While some major retailers are awarding free gift cards, discounts, and other incentives for the purchase of an iPhone X, most are not keen on trade-ins. But here are some other ways to cash in on an old phone.

Apple: The Apple Store generally offers store gift cards in exchange for old phones. You can currently get up to $325 for a fully owned iPhone 7 in good condition. And you don't have to use the gift cards on a new iPhone. But, as with the Big Four carriers, the trade-in value drops as phone models get older. According to Apple's website, an iPhone 5 is worth just $40.

Gazelle: On its website Thursday, Gazelle, which buys and sells used consumer electronics, offered $260 for an unlocked 32GB iPhone 7 in good condition. But the company warns that iPhone trade-in values will probably drop after the X launches. And, for those who want to get an early start, Gazelle says it will pay an extra 10 percent cash back for deals struck between now and Nov. 7. Once a deal is made, sellers have 30 days to mail their device to Gazelle, so no worries about being phoneless until you get your iPhone X.

If you'd rather not mail a phone to the company in a postage-paid envelope and await verification of its condition, you can also use the nationwide network of kiosks owned by parent company ecoATMs. The machine will examine your phone and make you an offer. If you accept it, you can receive your cash right away.

EBay and Craigslist: Websites like these will often produce bigger payouts for your phone, but they also require more effort on your part. So, before you go this route, be prepared to deal with the process of listing the product, responding to prospective buyers, and managing the exchange. But, for comparison's sake, a black pre-owned 256GB iPhone 7 sold for $550 on eBay in late September.

Should I Just Keep It?

If you’re only going to get a couple hundred bucks for your phone, though, you might be better off just hanging onto it.

If you take out the SIM card, making the device Wi-Fi only, you can still use it to take pictures or keep a fussy child happy with games on a long car trip.

Speaking of kids, if you’re thinking of getting one a phone for the first time, a hand-me-down is a good way to go, especially if you’re worried about the child losing or breaking it.

And, finally, if the worst happens and your beautiful new iPhone X breaks, your old phone can be a lifesaver. Instead of rushing to the Genius Bar to get it fixed, you can generally just pop the SIM card into your old phone and use it until the new one gets repaired.