Cheapest phone is $30 so you can get a blu candy bar phone and 3 months of mint sim for $30 + tax.
Regular price $45 for the 3 months of mintsim
Nice find! Thanks!
I've done the similar Best Buy discount for Simple Mobile, and resold the Simple Mobile refill card to reduce my phone cost. (I got a cheap BLU device to use as a backup phone, currently loaded with a FreedomPop SIM.) I think for most here, the MintSim offer is easily the best of the current promos.
This page describes the offer:
https://www.bestbuy.com/site/offer/244247/pcmcat1508170980385.c?id=pcmcat1508170980385
But the links to the card on that page aren't working for me, so:
https://www.bestbuy.com/site/promo/mint-sim-kits
In case one of the other similar promos works better for someone, there are links to the Boost, Simple Mobile, and Cricket offers on this page:
https://www.bestbuy.com/site/featured-offers/mobile-phone-cell-phone-sale/pcmcat125500050005.c?id=pcmcat125500050005
The details for each vary somewhat. The value comes either from being able to use the refill card, or being willing to resell it. (I'll note that when I looked at it, the Cricket offer specifically excluded BLU phones.)
(edit: oops, sorry to repeat mmfacemm's link!)
To save anyone else the time I tried to stack the cricket and mintsim offers and only one applies.
I may get this, because even with spotty tmobile service, this beats freedompop data prices by a long shot.
This should be under Mint SIM, not Other MVNO...
Yes sorry. I don't think I can change it...
We did talk about the cricket and simple deals though so I am a little off the hook!
Moto G 5th Gen would be great to pair with this deal! 
I hope that Best buy Will have lots of $10 unlocked phone for sale soon!