Brookings is not a bad town, but the pricetag is a bit high, Watertown is pretty good as well, but can't answer on price. Vermillion is another college town, and Ynankton isn't too bad, but I have no clue on the living there. Pricewise, probably higher, but it depends where you are at for pice as to what you consider high... Put it this way. I had a house out to Iroquois, cost $26,000, not a bad house. Same house in Brookings would be about $100,000.
Yankton and Vermillion will be more likely to use salt too, as they are further south. I was in the Huron-Brookings-Watertown area. Worked in Brookings for 5 years... I have been to Watertown a number of times. Depending what you are wanting, don't discount Aberdeen, that town has it going on, especially for being out as far as they are...