Welcome to the site from your neighbor to the north (ND)!
I went the same route and almost put the Masterbuilt smoker out at Sam's into my cart one day. I am glad that I researched and found the Smokin-It.
Actually "Old Sarge" from this site pointed the Smokin-It out to me on another smoking meat site that I was asking some questions on. I am glad that he suggested that I take a look at the Smokin-It.
Regarding the Auber, it is a cool tool to have, but by no means necessary to produce great BBQ. I have had my smoker for over a year now and haven't taken the plunge yet and have been putting out a lot of great food out of my smoker. It is nice to have for the programmability and ability to go higher than the 250 max of the stock controller (bypass needed for this). I have recently added the new side rails, seafood racks (for Jerky), and the Jerky fan to my arsenal. I think the Auber is the only thing left that I would really need/want. So, that maybe the next purchase. But I had other accessories that I thought were more important.