I cannot tell you how many CPR, first aid, advanced first aid and advanced life support classes I have taken. Courtesy of the U.S. Red Cross, the military and my employer. This may not make sense to you now, but the cost does not matter; here is why.
A few weeks ago my older son and I were having lunch - he had a hot dog, etc. I caught something out of the corner of my eye and looked. My son reached to his neck with the "I'm choking sign" and a look of complete terror on his face. I told him I understood, and because of all that training, I didn't have to think - I just reacted. I went over to him and did one Heimlich thrust and he started to wretch and cough. He was making progress, so no more thrusts. A second later he propelled a section of hot dog half way across the table. After a couple of quick breaths he looked up at me and smiled, and said "good Heimlich, dad."
I'm not telling you this because I think I'm brave or special in any way. I'm telling you this because of all the repetitive training that I didn't have to think: I just reacted.
If I had to think, I may have called 911. Big mistake, because when seconds count, 911 is only minutes away. He may have had a brain injury.
Take every class you can - you never know when you will use it. I NEVER imagined. In fact, you may even use the first aid training to save yourself.