Hi BowtothePhoenix,
I still have to laugh every time I type your username 
In any case … post #182 here includes the three factory direct manufacturers in the general Minneapolis/St Paul area and post #2 here includes these same three and a few of the local retail outlets that may provide some of the better “local value”.
As an aside … it still may be a useful idea to add a “lifting component” under the mattress soft spot (and check on some of the other possibilities in the post I linked to such as the foundation) just to see if it helps at all because the information you get from this may be helpful in your mattress search as well (it would indicate the importance of a suitable firmness in your support layers but more than anything highlight the effect of comfort layers that were too thick and soft for your body type and sleeping style).
Phoenix