Do you have a garden center that sells seed potatoes by the pound? You should and the cost should be about 1/10 of the cost of mail order, plus you don't pay shipping. Since it's an experiment I'd get maybe 5 pounds of seed potatoes and see how it goes.
I don't know what varieties grow well in Minnesota but I'd stick with a basic variety the first year. Do some research and see what varieties that would be. What kind of potato does your wife like, red skinned or white skinned? Maybe the yellow? My garden center has very little selection but has the basics, Kennebec for white, Pontiac Red for red, and lately they have Yukon Gold for Yellow. That's all they sell, none of the "craft" varieties. If she wants, get 2 or three pounds of each. You might be surprised at how productive they can be if they do well.
The seed potatoes they sell may have been treated with chemicals to break dormancy so they will sprout. So do not eat them, just plant them and grow them. Do not feed to animals.
It's been a while since we had a thread on growing potatoes. You can search but it might be good to start a fresh one. I don't think it's that hard but there are a few things about growing, harvesting, and storing them that might be good to revisit.