Hell, a standard 15 mm wrench does the job just fine. I mean, a vise grip or adjustable wrench would even work for the vast majority of pedals.

To the OP, SPD pedals aren't hard to clip in and out of. Do it a couple times leaning against the wall and then ride slowly around the neighborhood. No real need for a trainer. Adjust cleat position after you get used to riding them. If you feel like you need to, Google "spd cleat position" and read through a couple of the thousand articles that will pop up on what you're looking for when adjusting them.

I agree with MRT2. Pedal markup in LBS is pretty outrageous, rivaling or even surpassing groupset markup.