Quick, cheap firearms training is more expensive than you think.

Learning to shoot is not difficult but there's more to it than meets the eye.

Like any other sport, if you develop poor techniques, they are very hard to break. Unlearning always takes much more time than learning to do things right the first time. More time translates to additional correct training and more ammo -- obviously ammo is needed to shoot. Ammo, bulk or not, is expensive and getting more expensive each month.

Taking the "short cut", the cheap half-hour session with an RSO (Range Safety Officer) may result in poor shooting techniques.  An important point to remember is that an NRA RSO is NOT necessarily a certified instructor. If they were an instructor, the advertisement will have stated so. As will all things in life, the proof is in the pudding. If you can consistently shoot well after a half-hours session with a non-certified instructor, then you are very fortunate. If your shooting is not consistent, remember that continuing to shoot with poor techniques makes it harder to learn to shoot correctly. 

Unlearning bad habits and poor techniques always takes much more time than learning to do things right the first time.