Should i spend $30 on a new Blackberry Curve 3G or spend $200 on an Android Phone if I already own an itouch4g?

I need to get a new cellphone and I have a choice between Android and Blackberry and i own a 4th gen ipod touch...there is a price difference between the 2 but which one would be better for me? and i dont want my ipod to just sit there after i get the phone