Lately I have been seeing these companies come out with pretty good phones offering unlimited everything for 40-50 dollars. I am wonder if anyone has these phones? What the difference between those and the mainstream plans? Are you able to use these phones anywhere? Or Local only?
There are two types of phones, CMDA and GSM. Most are GSM since that is what most of the world uses. So depending on the type of service provider you are looking at you will be looking at one or the other type of phone. Technically any phone of that type *should* be able to work with that carrier, but it needs to be unlocked or able to easily be unlocked in order to bring the phone over to a new carrier that it wasnt bought with. Then the carrier might also have restrictions as well within their system for things like you cant activate a sim card with a 4G smartphone on their cheap unlimited plan. ATT had a big issue a while ago when people bought Galaxy Note phones and they were forcing users to buy a tablet plan (not a pay-as-you-go, prepaid unlimited, or standard smartphone contract plan) since ATT wanted to classify the phone as a tablet, didnt matter if you bought if through them or elsewhere. So you need to find more info on the carrier you are looking at specifically if you want to know any specific information. Part of looking into the carrier will also let you know which major company they lease network area from, which gives you a decent idea of cell service.
I was basically refering to the Prepaid plans as opposed to the mainstream providers. Is there any major difference.
Yes but some companies allow all phone on their prepaid unlimited plans, others do not. The carrier with the prepaid unlimited plan might use CDMA based phones, or GSM phones. You need to find out what the carrier you are looking allows for. Some of these plans also include 4G while others are only 3G data. I am assuming you want to use a phone with the plan right?