The Mesaba (aka NW Airlink) fares in MN have been higher than "usual" this summer, but your fare doesn't seem too bad.
You might want to watch fares out of LAS or ATL to BRD -- those two cities sometimes have better deals from North/Central MN. Of course, you'd still have to get to LAS/ATL
Be sure to watch for any zone based fare sales on Northwest -- they are usually also available on Mesaba operated flights (thanks Mesaba

). For example, you could save a bunch if you could go one the current NW 4th of July zone fare sale.
p.s. If you do make it via air to BRD -- watch how they unload your bags... Last time I had a stopover in BRD, instead of using a Tug to pull the bags to the terminal, they used a little John Deere tractor! I wondered if they also used it to mow the lawn

It was cute! Even though it was pretty funny, I've got to give them credit -- I'd bet that in Brainerd a John Deere repair shop is easier to find than than one for an airport Tug!