Looking at getting a used phone for cell nuvo or freedompop. I've found one that says sprint only, network locked and without contract. Would this work with cellnuvo or freedompop?
*** Probably the best way to be "sure" is to run the MEID or IMEI # on the Freedompop and CellNuvo elgibility ckeckers on their respective Websites, or call their CS.
"sprint only, network locked and without contract" is a big red flag and used by many sellers to avoid returns if it turns out the device will only activate on Sprint Post Paid.
You definitely need to ask the seller to Run the MEID through the Check Tool of the service(s) you want to use before you purchase the device and have them message you the exact results or ask them to verify that the device will activate on independent Sprint MVNOs.
If they will not do so, then move on to another seller.
As Isamorph says you need to run the MEID or buy from a seller that specifically states it works on a mvno.
On ebay if you want a low end phone for $20 then I'd recommend dealscaly. He/she has the LG F7 or htc desire 510 for $20. Condition is very good. Out of stock at the moment. You'd just need a sim which is easy to get. Sims from twigby are cheap and will work.
eg http://www.ebay.com/itm/401277422219?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Or just search for ringplus, tello etc and there are dealers there selling MVNO phones.
You can also buy one from c7recycle - they can make sure the meid works if you ask. Just pick a phone from the ringplus or tello sections.
What phone are you after and price you are looking to pay?
I'm looking to get a nice phone maybe the LG g4 .
There are a lot of resellers of those which makes it hard to find someone who will provide the MEID. Couldn't find anything from a quick glance. I'd be cautious getting a G4 as that model was full of bootloop issues.
Here is a LG G5 that checks out but is more expensive ...
http://www.ebay.com/itm/LG-G5-LS992-Latest-Model-32GB-GRAY-Sprint-Smartphone-9-10-/282458103894?hash=item41c3d0a056:g:Rz0AAOSwcgNZCXO0
The easiest phones are those that aren't tied to any carrier and can work on all of them - moto G4/G4 plus, Moto g5 plus, Nexus 5X, moto X pure. Some of those will be in your price range of close to it.
OK I forgot to check c7 also. I'll give that a look too. Ty all
Yes! IMO better to spend a little extra and have a device that, for the most part, you can take anywhere.
Over the last year I have transitioned our 3 primary devices over to carrier agnostic ones and I feel that we are much better off doing so. I have bounced between Sprint, ATT and VZW and to say it is convenient is an understatement.
Sold off most of my Sprint phones, have 2 SG Victories if anyone is interested. 
Not sure if this is the right thread for this or not.
Has anyone heard about this method to "unlock" an iPhone?
They are for sale on Amazon, but only one review so far. They must have just started selling these sim devices. Here's a you tube company video, if you haven't seen it yet. $30 is not bad, especially if can be used more than once. https://www.youtube.com/watch?v=neAR59rueJ8
***This is who is selling it on Amazon: MENANG8: Situs Slot Gacor Hari ini Gampang Menang Maxwin It's so new, it looks a bit suspisious to me.
So it looks like the added circuitry bypasses the iphone locks... wonder when Apple would issue an update to undo this hack...
Here is another similar product.
Yes- watched the video--looks good for $30 bucks.
By analyzing his iphone shake and hand movement, I have acquired his Apple ID and password. 
Would literally make these 2 deals a steal!
iPhone 6 with A8 processor
http://www.bestbuy.com/site/at-t-gophone-apple-iphone-6-4g-lte-with-32gb-memory-prepaid-cell-phone-space-gray/5838550.p?
iPhone SE with A9 processor
http://www.bestbuy.com/site/at-t-gophone-apple-iphone-se-4g-lte-with-32gb-memory-prepaid-cell-phone-space-gray/5792701.p?
Then just add $30 for the bypass circuitry.
I wouldn't mind pairing one of those unlock SIMs with one of these iPhone 6 phones on sale at Best Buy for $199.
Oh, even better deal... $160 for the SE.
http://www.bestbuy.com/site/total-wireless-apple-iphone-se-4g-lte-with-32gb-memory-prepaid-cell-phone-space-gray/5859430.p?
Save $40, pay $30 for the hack circuit... $190 plus tax and get an unlocked SE... very nice!
Is an SE better than a 6?
I'm not an iPhone person...
Whoa, just saw that the SE has a 4" display. That's ridiculously small. Even the 6 only has a 4.7".
In this day and age it seems silly to get anything smaller than 5".
The 6 has the A8 chip. SE has the newish A9 chip, like the 6S. As a FYI, iPhone 7 uses the A10.
Yep, screen sizes depends on your preference... I now only get screens at least 5.5".