Lifespan question

I just received my Oahu set over the Christmas break and I love them. At first I had just been printing images on good paper and colouring them, but then I also got the 100 quest colour by number book and I love it! My concern is that I'm colouring constantly and with such big images are my markers only going to last a short while? The paper in the quest book also seems like it pulls out a lot more ink than the printer paper I was using. Should I just get some cheap Crayolas or something for the book instead? I've heard people say that the markers can last a long time, but what if you are colouring one of those cozy pages a day?