Believe it or not, that seems like a reasonable price for a good class. Yelp it or find some other source of reviews to see if it seems like a quality program. For comparison, REI is collaborating with the Wilderness Medicine Institute of NOLS to offer a 2-day class that teaches wilderness medicine skills for $220 for members. In my past life I have gone through years of CPR and first aid training (every year for that job) and I need to get my skills updated again and the one I mentioned is the one I will be taking. Especially when it is something you don't do very often, it is good to practice the skill so you are ready when you do need it. And you never know when that will be. In practice, when backpacking I usually only see blisters, wear spots (the older packs used to wear holes in various areas around the hip belt), or coming down with the flu or cold when on trail. The worst I have seen is 1 broken arm and 1 rattlesnake bite, both very avoidable. Oh yea...and of course, when a teenager, the self-inflicted knife wounds . Almost forgot acute mountain sickness...I've seen plenty of that.

General survival school could be good; again look for reviews. Also keep in mind that plant information will tend to be location specific. All interesting stuff if you ask me... good for you for getting on it!

Knowledge is a powerful tool and is probably the most important thing you will carry with you backpacking.