I wanted to update this since I have had the Mingle for a month now. I have learned that if you go over your data limit without having the auto top up on that you get charged $2 and from that you run pay as you go at 2 cents a Mb on the free plan.
I did switch off of the 2 gig trial plan to the 500 Mb free plan. I also looked into Freedompop friends. With that program you either get 10 people to accept your invite, or you accept theirs and for each one you get 50 Mbs a month free. ( up to 10) So the 500 Mb plan becomes a 1 gig free every month. You can also get and give data back and forth for another 500 Mbs. I spent about 20 minutes copying and pasting emails listed on a few sites and in 24 hours about 50 people have accepted.
Other than that I have been watching for more deals on the hotspots. I can have multiple hopspots netting a gig free a month each and I have a few relatives that want them too. The last deal was hotspots for $29 and USB sticks for $19 but they sold out before I could get to them.