I remember a day when finding an unlocked phone was a task. It almost felt like buying something you are not supposed to do.
Now, you simply search for the term unlocked cell phone, or unlocked phones and the results are everywhere.
The most recent search took me to Amazon unlocked phones. there, I found plenty of phones.
You can also purchase unlocked cell phones directly from China, there are a lot of sites you can use, however, my favorite most secure site is Aliexpress.com Easy payment, multiple shipping options and buyer protection.