I also started out with the Prisma Pencils and got a large set. I will share my personal opinion about pencil coloring.
I like to color, and have ever since I was a little girl, lol. However, I got pretty frustrated with the amount of time it took to color using the pencils. I liked the idea of having so many colors to blend, but it seemed to take forever.... and then if you really want a nice blended look, you need to use the stumps and Gamsol.
I switched to markers which are SO much easier and quicker to use I think. I started with a couple of inexpensive sets of Bics and Sharpies, and filled in with a few Copics in lighter colors that I bought one at a time with coupons.
Then I found the Spectrum Noir markers. I got several 6 packs at Joann using a coupon. They retail for $14.99 there, and with a 40% or 50% coupon that is pretty reasonable.
I found more of them on sale online this fall before Christmas and filled in my sets.
I love coloring with markers in general, and love that the Spectrum Noir are so affordable compared to Copics.
Some people don't like coloring with markers and prefer pencils. Maybe you should get a set of Sharpies or Bics and see how you like the process of markers vs. pencils.
Bugga in OK
"Be kind whenever possible. It is always possible." Dalai Lama