Apple released the iPhone 7 last month and the world is still buzzing about it. The previous month, Samsung released—and then recalled—its wonder phone, the Galaxy 7S.

No matter what carrier you use for cellphone service, you are likely being bombarded, perhaps tempted, by offers to get a free or reduced upgrade.

Before you join the bandwagon of early adopters, you may want to ask yourself two questions:

1. Do I need a new phone?

2. Do I really get this new phone for free?

Every gadget company makes a big whoop-de-doo about their latest phone. It may have a 20 megapixel camera, a 4K screen, and the ability to resist bullets, but those features all have one thing in common: They will never be put to full use.

Even if you need a newer phone, you can probably get a much better deal on the previous generation. Before upgrading your perfectly good phone that you’re now used to, seriously evaluate how badly you need the new features of the latest phone. If you are just upgrading so that you can own the latest device, you could throw your contract agreement off for as much as two years.

Buying a new phone outside of contract typically costs between $500 and $1,200 depending on the phone. This is why cellphone companies increase the rates of their plans and add “nickel and dime” features to coincide with the releases of major phones.

Cell companies love to offer free phones, but almost all of these offers finance the phone over the long term. Some plans roll the cost of the phone into a two-year contract; others schedule the financing of the phone over a schedule that leaves the phone paid off at exactly the same time that the next generation of phone will come out.

Before you go to your carrier and get the new phone and, most likely, a new contract, figure out exactly how much you are paying for your current service for what you get.

Look up your account online and see how much data each person in the family is using and how much the total contract costs on each bill. Sometimes you are paying a lot more than you know because of overages or extra features you don’t even use.

Some companies have a phone service rate that doesn’t include the data or the phone financing. These plans may claim that your bill is $40 per month, but then you must pay an additional $35 per month if you want more than 1GB of shared data. Then they add on the cost of financing the phone. For an iPhone, this could be as high as $30 per month per phone.

Find out whether the phone is being subsidized (two-year contract must be complete before you can get another phone), financed (you can buy a new phone any time you want, but you may not own the phone until it’s paid off) or leased (you never actually own the phone, but you can trade in your perfect-condition phone once a year for an upgrade).

It’s always best to buy a new phone the way you would buy a new car. Shop around, ask lots of questions, discuss it with your friends and family, and do the math before you buy.