The Zoom B1on will do an octave up effect. I use it to get the 8 string sound. Not sure how it compared to the other dedicated pedals but it works decently and is very cheap. It's just over $100 here in Australia so probably closer to $60 in the US. As a bonus it works as a great headphone amp for practicing with Aux input to jam along to mp3's and a drum/rhythm machine.