Is Playing the Banjo Difficult?

I've been learning guitar for the past year and a half, and while I'm no expert, I'm still an intermediate player, having learned all the essential chords, strumming, finger-picking, barring, etc. Now I also wanted to start playing banjo (along with my guitar). I just wanted to know if is a difficult instrument to pick up on before I spent any money. I learned guitar fairly easily, I just wanted the opinion of someone with banjo experience.