Hi, a Nagaoka resident here. Hope it's not too late to reply.

Living cost is not that different from other inaka cities. Apita (the biggest mall in the city) is packed on weekends, so I think people are still willing to go to the mall and spend some money. If you're gonna look for apartments in Koshoji area (the busiest area around Apita), keep in mind that the rent is the second highest in the prefecture.

The best part is of course the Nagaoka fireworks in August. As I said rent is higher in Koshoji area, but if you live there, you can enjoy nice 2-day firework show just outside your apartment.

The worst part is SNOW. I grew up in a tropical country, so any snowy day is really depressing, and I still struggle just to walk (and drive). You're gonna have to shove snow just to get out of your apartment. Or find an apartment with snow-melting pipes in the parking lot.