I'm picking up a media streamer for my 70 year old mother. Has to be simple to use, reliable, and support most video file types/codecs. Also must have HDMI and a full size USB to play videos off of. Target price is around $100. Only thing is, she lives in the boondocks, so the only internet she has is a cellular mifi from Verizon with a 5GB cap per month. As a result the Media Streamer must support Wifi out of the box but only use very minimal amount of data in it's background usage (assuming she doesn't load a Netflix/YouTube movie obviously). Otherwise the Media Streamer must work well without any internet connection at all and she just wouldn't connect.
Suggestions? WDTV Live? Roku? I don't know how these would work without internet, or if internet was on, how much data they transfer just by turning the thing on. A couple of hundred megabytes transferred per month is fine, but 1GB is a problem.