Where are some good cities to live with housing priced under $100k?

Depends on what you value.

You can buy a house in Pittsburgh for around $100k, and there's some semblance of a tech space there (CMU, duolingo, self driving)

If language barrier is something you're willing to overcome, there are a wide array of areas to explore: Argentina comes up often (though I don't have any personal experience with it). Brazil is another option near it with municipalities that often resemble the US suburb feel (in Goias, Minas Gerais, etc for example) and has much warmer weather.

Charleston, WV is a place where your dollar goes very far. There are condos, lofts etc downtown or you could certainly get a small house in the suburban neigbhorhoods for under 100k. Although the state is backwater, Charleston being the capital has diverse food options, some nightlife, friendly people, and opportunities for physical activites (hiking, sports leagues etc). The weather patterns are great, too, you get 4 distinct seasons without extremely brutal summer or winter weather. Again since it is the capital it has a decent airport.

Morgantown, Lewisburg also worth checking out. Or maybe some of the mid-PA cities.

For a different vibe - Vegas might also be worth checking out. The real estate market there cratered during the last recession, I imagine it's doing pretty bad right now as well. Lots of food/entertainment there and direct flights to everywhere.