You ignored the rest of my post. You can't get the phone for that price because of the additional fees charged by the 3rd party sellers. There is no way Walmart doesn't charge one of those. For instance, Walmart Wireless online charges $400 if you don't return the phone and the box and everything it comes with in good condition if you cancel before 14 days which would mean no ETF and no activation fee, but the phone would end up costing you $127 + $400 = $527. So you would save $650 - $527 = $123.
I guess that is worth it to some people, but it seems like a lot of work to me for $123.
You're probably right that it isn't the best idea, but whether you pay $350 or $400 to cancel within 14 days doesn't seem that critical to me since I assume you would be charged one or the other.
I would be concerned if you cancel or make changes before 181 days but after the 14th day, since I know places like Amazon and perhaps Walmart can charge you $400 as you mentioned.
However, I believe Verizon Wireless still has the right to charge you the normal ETF of up to $350 on their end as well.
That could mean getting hit from both sides. Here are part of the Terms for AmazonWireless:
The following are some scenarios where we may determine that you have not maintained your service and have not met the requirements listed above:
If your device with the carrier is not activated per Amazon's activation instructions within 14 days
If your service is canceled/disconnected before 181 days and you do not return the device(s) to Amazon
If a new individual or new family account is merged with or replaces a pre-existing account
If you transfer this equipment to another carrier's service or to another line in your family account and deactivate the line that Amazon established for your device
By accepting this Instant Discount Policy, you agree to repay $400 per smart phone or tablet and $200 per other device if you do not maintain your carrier service for 181 consecutive days from the service activation date. You also authorize us to collect that amount using any credit card we have on record for you. Amazon can periodically check your account status with the carrier to confirm your line of service is active and in good standing and thereby confirm you are in compliance with this policy.
The Instant Discount Policy will not be applied if you cancel your order and return the device(s) within our 30-day return period. You must return your device(s) to Amazon within the carrier's 14-day return period in order to avoid the carrier's Early Termination Fees (ETF). If your purchase was an upgrade, your upgrade eligibility will not be reset unless you return your device to Amazon within the carrier's 14-day return period