Yes they are definitely worth buying. My son-in-law and I both taught ourselves to fly on GP RealFlight G2 simulators about fifteen years ago. We had no choice, there was no one in the area to teach us. We both worked with the sims over the winter and when spring rolled around, we were both successful and were able to take off, fly and land without crashing. Maybe we were lucky, but the sims sure didn't hurt. I snow have RealFlight 6.5 and practice with it frequently. They are fairly close to the real thing. Add wind from differing directions and speeds, thermal activity etc. to add extra challenges, but also get help from an instructor of possible.
bhady