I decided to try this whole "alcohol marker thing" around a year and a half ago and I started with Prismacolor Markers because I could get them at the local craft store using a coupon. When I realized how much I loved coloring with markers I made the investment in Copics because of the refill capabilities and I love the brush like nib! I used to paint with watercolors and I feel like I can get a similar look (although more intense) without the messiness by using Copics.
I am not Copic certified and have not taken any classes. I have spent a lot of time studying other peoples work with copics, and I get so much out of seeing what colors they used so I always make sure I list the colors I use on my cards. I really love the feeling of bringing an image to life just by coloring!