Which hair product should I use to make my hair grow faster?

Ok so I dyed my hair 6 months ago and I'm sick of the color but I don't want to dye it again. I just want it to grow out! So...I've been researching different products that supposedly help your hair grow fast. I'm trying to decide between Mira Hair Oil and Wild Hair Growth. The price difference is HUGE...so question is this...is Mira Hair Oil really worth it to spend 60-70 bucks compared to spending 7-10 bucks on Wild Hair Growth?