not sure when the ad started or ends by the Brightspot Nokia 521 is on sale for $64.99 at Target! Brightstpot uses Tmobiles network. The phone doesn't say Tmobile on the bottom of the phone.
I can confirm this phone works just fine on tmobile. Wife to went to tmobile store to swap sim chip from reg to mini for free. One guy game her a hard time and said she'd have to go back to Target, but this other girl helped my wife and got it working good for her.