Is it difficult to find places to hunt them? I would like to start but not sure how hard it would be to locate / acquire access to hunt them. Been doing some research on line and was really surprised by what some of the guides / outfitters charge if you go that route.
We have some in Kansas and I shoot them occasionally. It's one of my favorite off-season activities. "The ask" is usually pretty easy--I've rarely been told no. The hard part is finding the towns and identifying a landowner.
When I first started looking for towns to shoot about 15 years ago, I called the extension agents in counties that I thought were possibilities. Most land-grant universities have "extension" services with offices around the state with the purpose of helping producers. Anyway, I called the extension agent for county X, told them what I wanted, and most of them gave me a producer name or two and phone number. Then I called the producers, "out of the blue" from their perspective, told them how I got their name and what I wanted. Every one of them told me yes. Not all the towns were worth shooting, but some were. There's sometimes a difference between what a producer considers a big prairie dog town and a prairie dog town that's worth setting up to shoot.
All of my towns are day-trips from Wichita and none are big enough to attract a person to drive from Wisconsin. Kansas has some of those, but they're a long way from Wichita.
Western SD is filled with some very large, bordering on massive, dog towns. When I was a kid, in the 90's, we used to shoot a lot of them on the land that we deer and antelope hunted on. Now there are a lot of people that are charging to shoot them. Still have some guys that will let us shoot them though. I personally am not going to pay to shoot them. Seeing how they will basically destroy a pasture I'm not going to pay to fix someone's problem. If they want me to shoot them so they can reclaim their pasture and make it useful again I'll kill dogs all day long.
Used to shoot some big dog towns in Wyoming back in the 80s. I don't think I've ever heard of a dog town getting shot out completely. The only thing I ever heard of that really gets rid of them is gassing them. Even then they may come back.
As far as pay-to-shoot for pests, I'm a non-player. There's constant talk about feral hogs ruining farms in Texas but that's all pretty much pay-to-shoot as well.