Hello Michael,
If you grew up in Montana, why forsake where you were raised? As someone raised in the Black Hills and now returned from the mid-Atlantic region for retirement life, I'd venture that the two states share many similarities. Montana's way more impressive by many measures. I'd also suggest more of the Treasure State has been discovered by big city folks with money - tons of it. But you have asked about South Dakota.
Weather: Be prepared for "authentic" experiences across all seasons. Don't, like we did, forget about the wind. The truck-tipping zephyrs far out number days of calm or gentle breezes.
Taxes: No income tax (whoopee, if that's your thing), but property taxes will grab your attention and wallet, harder than you might imagine. Sales tax is calculated for almost everything, 4.5 percent for the state and often another 2 percent for local needs, and higher yet for purchases related to tourism.
Hunting/fishing: Better than some places in the High Plains region, but locals grumble that deer hunting isn't what is once was. Rural landowners are quickly catching on to offering experience-flavored hunts with posted land (the good stuff), guides, resort-style cabins, etc. Fishing opportunities are more abundant, likewise boating and even sailing (remember, it's windy) on the big reservoirs.
Tourism: We're not quite there, but signs of "loving South Dakota to death" are starting to show. There's the bike rally in Sturgis, known as the world's biggest, noisy party/flea market/rock concert. If you're into burning hydrocarbons on two wheels (or three), then party on. Otherwise, join the locals who endure the crowds and possibly figure out some way to make a little (or a lot) of money by serving the visitors.
Real estate: Others have already commented about this question. The Black Hills region and major population centers across the state, especially Sioux Falls, have been discovered. The bargains are gone. That said, if you can afford it, real estate agents have big portfolios of property with anything you could want. Just be prepared to pay. Shop carefully lest you buy your dream acreage in a beautiful place where zoning regulations (or lack thereof) might put you next door to current or future neighbors who think, act and behave in ways you find offensive. More affordable properties are out there, but be ready to move to a small town or rural place far out on the prairie.
Bonus: Sawmill Creek is about woodworking. Since moving back home several years ago, I've filled our garage to bursting with affordable woodworking tools of all types that I've purchased at auctions. Good deals in this arena remain as the population of local woodworkers dwindles. If you are a skilled woodworker and want to remain in the workforce in South Dakota, bring your tools and your best game. As with many other parts of the country, craftspeople of all disciplines are in short supply. Whether you're a nailgun shooter who can frame houses or a skilled remodeler who isn't afraid of tackling complex projects for homeowners, there's plenty of opportunity. Don't forget to pack your long underwear and a warm hat.