How to remove iCloud activation lock?

H I recently purchased an iPhone 5 off of eBay. It's for verizon and it did not come with a SIM card. The seller claims it is iCloud locked but I don't know if that's true because it stops and tells me to put in a SIM card. I was wondering if their was a way to bypass all of this so it could be used just as an iPod? If not then could anyone give me an estimate of what it's worth it's practically in mint condition.

This tutorial will show you how to turn off iCloud on any iPhone, iPad, or iPod Device

When you turn off the iCloud feature on your iPhone, iPad, or iPod Device, your up-to-date iCloud information for that feature is no longer available on it. In many cases when you turn off a feature, you're asked whether you want your device to keep a copy of your information stored in iCloud for that feature. You don't need to keep a copy if you have other devices set up for the same feature, because your information is still available on them. For example, if your iPhone and iPad both have Contacts turned on, you can turn off Contacts on your iPad without keeping a copy of your iCloud contacts on it, and still access those contacts on your iPhone. If you turn Contacts on again on your iPad, your latest contact information reappears on it automatically.

Before turning off a particular feature on all your devices, or before turning off iCloud completely, you can archive a copy of your iCloud data on your computer
Turn iCloud features on or off

Depending on which device's settings you want to change, do one or more of the following:

On your iOS device's Home screen, go to Settings > iCloud, then tap to turn on or off iCloud features.