I was in the same boat as you are in for about four years trying to improve.
I was always told that blades were reserved for the best golfers. This meant there were about 1-2 people in my city of 60,000 people that should use them. That came from two separate pros from two local courses.
Here is a guy that disagrees with that: www.oobgolf.com/content/the+wedge+guy/golf+equipment/5-2032-Blades_Versus_Cavity_Backs_A_Golf_Club_Epiphany.html
If you think it's worth the money I would go with blades. Swing trainers usually only focus on one aspect of the swing.
However, what helped me become better was reading a book about the mental game, specifically Mind Over Golf (I know it sounds ridiculous). Also, recent research has determined that GIR is the best predictor of score. Whatever you can do to improve GIR might be the key to lowering your score.