I get asked this now and again- the long and short of it is I can't afford one. Sad, I know, but it is what it is. I had one once for a year by way of a gift, and it was pretty rad. One day, my creative work will garner the extra coin beyond paying bills to be able to spring for extras like a Premium DA account. Until then, I hope you all don't mind that I rely on the free model- though I know some have complained.
Bear with the freelance artist/writer. It's not exactly a fully bankrolled operation